Don't Wait. Donate!
If you take your fellow's garment as security, until sunset shall you return it to him. ...so it will be that if he cries out to Me, I shall listen, for I am compassionate. (Ex. 22:25-26)
The Torah commands us to lend money to our fellow Jews. If the borrower does not repay, the lender may ask the court that he be given an item as collateral. However, the lender must return the collateral to the borrower at the times when he needs it. If the lender does not return it, he will be punished since God listens to the cries of the borrower.
One may ask: the lender has rights to an object of the borrowers. He needs to insure that he gets his money back. What then is the sin of not returning the collateral to the borrower when he needs it - the lender should be able to demand his money back if the borrower has to have his collateral?
God gives a person more than what he needs for survival, merely for helping and giving to others. A person must look at the spare money he has as a deposit from God to assist the needy. Therefore, in a sense the lender has an obligation to lend out his extra money and doesn't deserve any collateral for it. However, the Torah has given him rights to take collateral so that he can keep lending his money to others. Still, when the borrower needs the coat the lender has to return it - out of the knowledge that nothing, even his own possession, is truly his.(1)
The Talmud(2) relates that Turnus Rufus, the Roman Governor of Judea, asked Rabbi Akiva: "If your God loves the poor, why does He not support them?" Rabbi Akiva replied, "So that we may be saved from the punishment of Hell by giving charity." God gives me extra so that I can gain by helping others. With this in mind, when someone comes and asks to borrow something, instead of making up a poor excuse try lending it out and saying "Thank you for giving me this opportunity!"
2. Baba Basra 10a.