Overall meaning :
Allah commands His Prophet Muhammad, may Allah bless him and grant him peace, to take charity from the Muslims’ wealth to purify them thereby and cleanse them thereby of the stains of their sins. He also instructs him to pray for them upon taking it, as his prayers comfort their hearts and provide a source of tranquillity for them. Allah is All-Hearing, All-Knowing.
Do they not know that it is indeed Allah alone who accepts repentance from those who repent and accepts His servants’ charity, and that He is the Acceptor of Repentance, the All-Merciful?