You shall surely give him, and your heart shall not be grieved when you give to him, because for this thing Hashem your God will bless you in all your work and in all that you put your hand to.
English: "You shall surely give" — From where do we know that if you have given him once you must give him even a hundred times? From the doubled language "give, you shall give"—in every case.
On the daf / in context: Charity has no upper limit of frequency; the obligation continues throughout life.
Type of Learning
Derash on the verse (Bava Metzia) — repeated giving is required.
What Is Learned
One must continue to give to the same needy person even a hundred times; the mitzvah does not end after a single gift.