Maliks Muwatta Book 21, Hadith Number 14.
Yahya related to me from Malik from Yahya ibn Said that Said ibn al-Musayyab used to say, “When a man is given something to use in a military expedition, and he brings it to the battlefield, it is his.”
Malik was asked about a man who pledged himself to go on a military campaign, equipped himself, and when he wanted to go out, one or both of his parents prevented him. He said, “He should not contradict them. Let him put it off for another year. As for the equipment, I think that he should store it until he needs it. If he fears that it will spoil, let him sell it and keep its price so that he can readily buy what is needed for a military expedition. If he is well-to-do, he will find the like of his equipment when he goes out, so let him do what he likes with his equipment.”