By asking forgiveness from Allah, Allah erases sins. Allah says:“And those who, when they have committed Fahishah (illegal sexual intercourse etc.) or wronged themselves with evil, remember Allah and ask forgiveness for their sins; - and none can forgive sins but Allah - And do not persist in what (wrong) they have done, while they know.” {135} (Surat Al-Imran).
Allah says: “And whoever does evil or wrongs himself but afterwards seeks Allah's Forgiveness, he will find Allah Oft Forgiving, Most Merciful.” {110} (Surat An-Nisa’).
Ibn Mas’ud said: the Messenger of Allah said: “He who says: ‘Astaghfir ullah-alladhi la ilaha illa Huwal-Haiyul-Qayyumu, wa atubu ilaihi (I seek the forgiveness of Allah, there is no true god except Allah, the Ever-Living, the Self-Subsisting, and I turn to Him in repentance),’ his sins will be forgiven even if he should have run away from the battlefield (while he was engaged in fighting for the Cause of Allah).” [Abu Dawud, At-Tirmidhi and Al-Hakim (on conditions of Al-Bukhari and Muslim for accepting Hadith)].
On the authority of Anas who said: I heard the Messenger of Allah saying: “Allah, the Exalted has said: O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you. O son of Adam, were you to come to Me with sins nearly as great as the earth and were you then to face Me, ascribing no partner to Me, I would bring you forgiveness nearly as great as it.” (At-Tirmidhi).
Forgiveness cleans and purifies the souls and hearts. It is said: the one, who is constantly asking forgiveness of a sin from Allah, is without a sin. In addition, forgiveness is a means of increasing provision as Allah says on the Prophet Noah’s tongue when he was promising his people:
"I said (to them): 'Ask forgiveness from your Lord; Verily, He is Oft-Forgiving; 'He will send rain to you in abundance; {11} 'And give you increase in wealth and children, and bestow on you gardens and bestow on you rivers.' " {12} (Surat Nuh).
The Prophet Mohammed (peace be upon him) advised us to seek forgiveness for ourselves and for all Muslims. Allah says:
“And ask forgiveness for your sin, and also for (the sin of) believing men and believing women.” {19} (Surat Mohammed).
Al-Agharr Al-Muzani said: the Messenger of Allah said: “Sometimes I perceive a veil over my heart, and I supplicate Allah for forgiveness a hundred times in a day.” (Muslim).
It was narrated by Abu Hurairrah that he said: I heard the Messenger of Allah saying: “By Allah! I seek Allah’s Forgiveness and turn to Him in repentance for more than seventy times a day.” (Al-Bukhari).
Ibn ‘Umar said: We counted the Messenger’s saying a hundred times during one single sitting: “Rabb-ighfir li, wa tubb ‘alayya, innaka antat-Tawwabur-Rahim. (MyRubb! Forgive me and pardon me. Indeed, You are the Oft-Retunrning with compassion and Ever Merciful.” (Abu Dawud and At-Tirmidhi).
The Messenger of Allah advised us to constantly seek forgiveness, in particular before his death. Allah says:
“So glorify the Praises of your Lord, and ask for His Forgiveness. Verily, He is the One Who accepts the repentance and forgives.” {3} (Surat An-Nasr).
Aishah reported: Prior to his demise, the Messenger of Allah used to supplicate frequently:
“Subhan Allah wa bihamdihi; Astaghfir-ullah wa atubu ilaihi (Allah is free from imperfection, and I begin with praising Him. I beg forgiveness from Allah and I turn to Him in repentance.” (Al-Bukhari and Muslim).
Furthermore, forgiveness takes away distress and brings forth provisions. Ibn ‘Abbas said: the Messenger of Allah said: “If anyone constantly seeks pardon (from Allah), Allah will appoint for him a way out of every distress and a relief from every anxiety, and will provide sustenance for him from where he expect not.” (Abu Dawud).
Allah loves people who asking forgiveness. Allah says:
“And seek the Forgiveness of Allah, certainly, Allah is Ever Oft Forgiving, Most Merciful.” {106} (Surat An-Nisa’).
It was related that Abu Hurairrah said that the Messenger of Allah said: “By The One in Whose hand is my soul, had you not committed sin, God would remove you and replace you with another people who would sin and then they would seek God’s forgiveness, so He would forgive them.” (Muslim).
Allah promised the believer who asking forgiveness from Allah as Allah says:
“For Al-Muttaqun there are Gardens” {15} (Surat Al-Imran).
Allah sent punishment down to the previous nations if they didn’t believe their prophets. But with His great Mercy upon our nation, Allah promised not send punishment as long as the Prophet Mohammed is alive, and after his death as long as we ask forgiveness from Allah. Allah says:
“And Allah would not punish them while you (Muhammed pbuh) are amongst them, nor will He punish them while they seek (Allah's) Forgiveness.” {33} (Surat Al-Anfal).
Keep reciting the most superior way of asking forgiveness with firm faith in it and you will be from the people of Paradise.
It was narrated by Shaddad bin Aus: The Prophet said "The most superior way of asking for forgiveness from Allah is: 'Allahumma anta Rabbi la ilaha illa anta, Anta Khalaqtani wa ana abduka, wa ana 'ala ahdika wa wa'dika mastata'tu, A'udhu bika min Sharri ma sana'tu, abu'u Laka bini'matika 'alaiya, wa Abu Laka bidhanbi faghfirli innahu la yaghfiru adhdhunuba illa anta" (O Allah, You are my Lord; none has the right to be worshipped, except You. You created me and I am Your servant and I abide by Your covenant and promise as best as I can. I seek refuge in You from the evil of what I have committed. I acknowledge Your favour on me and I acknowledge my sin, so forgive me, for verily no one can forgive sins, except You). The Prophet added. "If somebody recites it during the day with firm faith in it, and dies on the same day before the evening, he will be from the people of Paradise; and if somebody recites it at night with firm faith in it, and dies before the morning, he will be from the people of Paradise." (Al-Bukhari).
Thauban reported: Whenever the Messenger of Allah finished his prayer, he would beg forgiveness three times [by saying, ‘Astaghfirullah’ (3 times)] and then he would say:
“Allahumma Antas-Salamu, wa minkas-Salamu, tabarakta ya Dhal-Jalali wal-Ikram. (O Allah! You are the Bestower of security and security comes from You; Blessed are You. O Possessor of glory and honour).” Imam Al-Auza’I (one of the subnarrators) of this Hadith was asked: “How forgiveness should be sought?” He replied: “I say: Astaghfirullah, Astaghfirullah (I seek forgiveness from Allah. I seek forgiveness from Allah).”(Muslim).
We ask Allah’s forgiveness if there are any shortcomings, forgetfulness or mistake, Ameen.
http://en.alukah.net/Shariah/0/1162/
Allah says: “And whoever does evil or wrongs himself but afterwards seeks Allah's Forgiveness, he will find Allah Oft Forgiving, Most Merciful.” {110} (Surat An-Nisa’).
Ibn Mas’ud said: the Messenger of Allah said: “He who says: ‘Astaghfir ullah-alladhi la ilaha illa Huwal-Haiyul-Qayyumu, wa atubu ilaihi (I seek the forgiveness of Allah, there is no true god except Allah, the Ever-Living, the Self-Subsisting, and I turn to Him in repentance),’ his sins will be forgiven even if he should have run away from the battlefield (while he was engaged in fighting for the Cause of Allah).” [Abu Dawud, At-Tirmidhi and Al-Hakim (on conditions of Al-Bukhari and Muslim for accepting Hadith)].
On the authority of Anas who said: I heard the Messenger of Allah saying: “Allah, the Exalted has said: O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you. O son of Adam, were you to come to Me with sins nearly as great as the earth and were you then to face Me, ascribing no partner to Me, I would bring you forgiveness nearly as great as it.” (At-Tirmidhi).
Forgiveness cleans and purifies the souls and hearts. It is said: the one, who is constantly asking forgiveness of a sin from Allah, is without a sin. In addition, forgiveness is a means of increasing provision as Allah says on the Prophet Noah’s tongue when he was promising his people:
"I said (to them): 'Ask forgiveness from your Lord; Verily, He is Oft-Forgiving; 'He will send rain to you in abundance; {11} 'And give you increase in wealth and children, and bestow on you gardens and bestow on you rivers.' " {12} (Surat Nuh).
The Prophet Mohammed (peace be upon him) advised us to seek forgiveness for ourselves and for all Muslims. Allah says:
“And ask forgiveness for your sin, and also for (the sin of) believing men and believing women.” {19} (Surat Mohammed).
Al-Agharr Al-Muzani said: the Messenger of Allah said: “Sometimes I perceive a veil over my heart, and I supplicate Allah for forgiveness a hundred times in a day.” (Muslim).
It was narrated by Abu Hurairrah that he said: I heard the Messenger of Allah saying: “By Allah! I seek Allah’s Forgiveness and turn to Him in repentance for more than seventy times a day.” (Al-Bukhari).
Ibn ‘Umar said: We counted the Messenger’s saying a hundred times during one single sitting: “Rabb-ighfir li, wa tubb ‘alayya, innaka antat-Tawwabur-Rahim. (MyRubb! Forgive me and pardon me. Indeed, You are the Oft-Retunrning with compassion and Ever Merciful.” (Abu Dawud and At-Tirmidhi).
The Messenger of Allah advised us to constantly seek forgiveness, in particular before his death. Allah says:
“So glorify the Praises of your Lord, and ask for His Forgiveness. Verily, He is the One Who accepts the repentance and forgives.” {3} (Surat An-Nasr).
Aishah reported: Prior to his demise, the Messenger of Allah used to supplicate frequently:
“Subhan Allah wa bihamdihi; Astaghfir-ullah wa atubu ilaihi (Allah is free from imperfection, and I begin with praising Him. I beg forgiveness from Allah and I turn to Him in repentance.” (Al-Bukhari and Muslim).
Furthermore, forgiveness takes away distress and brings forth provisions. Ibn ‘Abbas said: the Messenger of Allah said: “If anyone constantly seeks pardon (from Allah), Allah will appoint for him a way out of every distress and a relief from every anxiety, and will provide sustenance for him from where he expect not.” (Abu Dawud).
Allah loves people who asking forgiveness. Allah says:
“And seek the Forgiveness of Allah, certainly, Allah is Ever Oft Forgiving, Most Merciful.” {106} (Surat An-Nisa’).
It was related that Abu Hurairrah said that the Messenger of Allah said: “By The One in Whose hand is my soul, had you not committed sin, God would remove you and replace you with another people who would sin and then they would seek God’s forgiveness, so He would forgive them.” (Muslim).
Allah promised the believer who asking forgiveness from Allah as Allah says:
“For Al-Muttaqun there are Gardens” {15} (Surat Al-Imran).
Allah sent punishment down to the previous nations if they didn’t believe their prophets. But with His great Mercy upon our nation, Allah promised not send punishment as long as the Prophet Mohammed is alive, and after his death as long as we ask forgiveness from Allah. Allah says:
“And Allah would not punish them while you (Muhammed pbuh) are amongst them, nor will He punish them while they seek (Allah's) Forgiveness.” {33} (Surat Al-Anfal).
Keep reciting the most superior way of asking forgiveness with firm faith in it and you will be from the people of Paradise.
It was narrated by Shaddad bin Aus: The Prophet said "The most superior way of asking for forgiveness from Allah is: 'Allahumma anta Rabbi la ilaha illa anta, Anta Khalaqtani wa ana abduka, wa ana 'ala ahdika wa wa'dika mastata'tu, A'udhu bika min Sharri ma sana'tu, abu'u Laka bini'matika 'alaiya, wa Abu Laka bidhanbi faghfirli innahu la yaghfiru adhdhunuba illa anta" (O Allah, You are my Lord; none has the right to be worshipped, except You. You created me and I am Your servant and I abide by Your covenant and promise as best as I can. I seek refuge in You from the evil of what I have committed. I acknowledge Your favour on me and I acknowledge my sin, so forgive me, for verily no one can forgive sins, except You). The Prophet added. "If somebody recites it during the day with firm faith in it, and dies on the same day before the evening, he will be from the people of Paradise; and if somebody recites it at night with firm faith in it, and dies before the morning, he will be from the people of Paradise." (Al-Bukhari).
Thauban reported: Whenever the Messenger of Allah finished his prayer, he would beg forgiveness three times [by saying, ‘Astaghfirullah’ (3 times)] and then he would say:
“Allahumma Antas-Salamu, wa minkas-Salamu, tabarakta ya Dhal-Jalali wal-Ikram. (O Allah! You are the Bestower of security and security comes from You; Blessed are You. O Possessor of glory and honour).” Imam Al-Auza’I (one of the subnarrators) of this Hadith was asked: “How forgiveness should be sought?” He replied: “I say: Astaghfirullah, Astaghfirullah (I seek forgiveness from Allah. I seek forgiveness from Allah).”(Muslim).
We ask Allah’s forgiveness if there are any shortcomings, forgetfulness or mistake, Ameen.
http://en.alukah.net/Shariah/0/1162/