:salam2:
Am not too sure exactly but i think they mean : -
the Five pillars of Islam and six Pillars or faith -
The word Tayyabah means Purity.
Allah says in the Qurán ...
“Do you not see how Allah puts forth the likeness of a good word (kalimah tayyibah)? It is like a good tree, whose root is firmly fixed and whose branches reach to the sky. It brings forth its fruit in all seasons by the command of its Lord. And Allah sets forth parables for men, so that they may take heed. And the likeness of an evil word (kalimah khabeetha- a word of shirk) is like an evil tree, which is uprooted from the face of the earth, and has no stability.” (Quran XIV: 24-26)
Allah Knows best.