As explained, the mitzvah of giving a loan is similar to the mitzvah of giving tzedakah in that both must be done with a smile. Therefore, if, for whatever reason, one cannot give his fellow a loan, he should nevertheless speak encouraging words and show the fellow his good heart — that he would have gladly given him a loan but that he is not in the position to do so. One must not yell or shame the fellow, as is the way of stingy people; they not only refuse to give loans but they also raise their voice and shout at those who ask for a loan.
The general rule is this: Whichever way a person would want others to treat him if he were seeking a loan, so should he treat others. Our Sages said: One who greets his fellow with a pleasant face, even if he gives him nothing, it is considered as though he gave him all the gifts in the world.