Ijow 30:25 Halacha: Kitzur Shulchan Arukh

Whoever gives charity to a poor person with an angry countenance, even if he gives a thousand gold pieces, he has forfeited his merit [reward], and he violates the prohibition: "Your heart shall not be sorry [when you give him charity]."¹⁹Deuteronomy 15:10. But rather you must give to him with a smiling countenance and with joy, and commiserate with his suffering, as Job said: "Did I not cry for the troubled, was my soul not grieved for the needy."²⁰Job 30:25. And speak to him words of comfort as it is said: "And the heart of the widow, I caused to sing for joy."²¹Job 29:13.