If you disclose your alms, even then it is well done, but if you keep them secret, and give them to the poor, then that is better still for you; and this wipes off from you some of your evil deeds

Take alms out of their property, you would cleanse them and purify them thereby, and pray for them; surely your prayer is a relief to them; and Allah is Hearing, Knowing. (The Immunity 9.103)

And whatever alms you give or (whatever) vow you vow, surely Allah knows it; and the unjust shall have no helpers.

This is that he might know that I have not been unfaithful to him in secret and that Allah does not guide the device of the unfaithful.

So they disputed with one another about their affair and kept the discourse secret.

Have you not seen those who are forbidden secret counsels, then they return to what they are forbidden, and they hold secret counsels for sin and revolt and disobedience to the Apostle, and when they come to you they greet you with a greeting with which Allah does not greet you, and they say in themselves: Why does not Allah punish us for what we say? Hell is enough for them; they shall enter it, and evil is the resort.