The sidra says, “If your brother has become poor and his means have failed, you shall uphold him; as a stranger and settler shall he live with you” (Lev. 25:35).
“As a stranger and settler” does not mean treating him like a second-class citizen. Rashi says, “Even though he is a stranger and settler”, i.e. whether he is native-born or a newcomer, he is still your brother and you must help him.
“You shall uphold him” means that you must not wait until he has totally collapsed; the moment he shows signs of falling, you must be there to give him support.
How much support must you give him? “Uphold him so that he can live with you” – so that he can face you with dignity.
When must you help him? Now, when the need exists: “he shall live with you”, while you and he are both alive.
Every credit is due to those who bequeath money to charity in their will, but hopefully they will live for many more years – and if the need is there now, now is the time to do something about it.
“Later is too late” is a good Jewish principle. It applies not only in giving but also in learning (“Do not say, ‘When I have leisure I will study’, says Pir’kei Avot; “perhaps you will have no leisure”).
In observing mitzvot, later is too late: “If a mitzvah comes to your hand,” the sages say, “do not let it become stale” (commentaries on Ex. 12:17).