Quran 2:264 — The Heifer (Al-Baqarah)

O you who believe, do not nullify your charities by inflicting reproach and insult, like one who spends his money to show off, while disbelieving in GOD and the Last Day. His example is like a rock covered with a thin layer of soil; as soon as heavy rain falls, it washes off the soil, leaving it a useless rock. They gain nothing from their efforts. GOD does not guide disbelieving people.

[2:263] Kind words and compassion are better than a charity that is followed by insult. GOD is Rich, Clement.

[2:265] The example of those who give their money seeking GOD's pleasure, out of sincere conviction, is that of a garden on high fertile soil; when heavy rain falls, it gives twice as much crop. If heavy rain is not available, a drizzle will suffice. GOD is Seer of everything you do.