(If I catch this bird, I will sell it to you) Is a sale like this permissible?

Question:
May Allah reward you. Your Eminence, the father, the questioner says: If a person says to another, "If I catch this bird, I will buy it from you," is that permissible? No.

Answer:
It is not permissible to sell a bird, even if one owns it. If one owns it and it is flying, it is not permissible to sell it, because it is not possible to deliver it. One of the conditions for the validity of a sale is the ability to deliver the item. They gave as an example that it is not permissible to sell a bird in the air, a fish in the water, a stray camel, or a runaway slave, until one is able to take possession of these things, at which point he may sell them. Yes.