Halakha Ayub 29:13: Mishneh Torah, Gifts to the Poor & Kitzur Shulchan Arukh

Anyone who gives tzedakah to a poor person with a scowl and causes him to be embarrassed,¹⁸³Literally: causes his face to fall in shame. even if he gave him a thousand zuz, has destroyed and lost any merit thereby. Rather, one should give cheerfully, with happiness [to do so] and empathy for his plight, as it is said, (Job 30:25) Did I not weep for the unfortunate? Did I not grieve for the needy? And one should speak to him words of comfort and consolation, as it is said, (Job 29:13) [I received the blessing of the lost,] I gladdened the heart of the widow.

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.