Deuteronomy 15:10 in the King James Version
Thou shalt surely give him, and thine heart shall not be grieved when thou givest unto him: because that for this thing the LORD thy God shall bless thee in all thy works, and in all that thou puttest thine hand unto.
Context
9 Beware that there not be a wicked thought in your heart, saying, “The seventh year, the year of release, is at hand,” and your eye be evil against your poor brother and you give him nothing; and he cry to the LORD against you, and it be sin to you.
10 You shall surely give, and your heart shall not be grieved when you give to him, because it is for this thing the LORD your God will bless you in all your work and in all that you put your hand to.
11 For the poor will never cease out of the land. Therefore I command you to surely open your hand to your brother, to your needy, and to your poor, in your land.