He was asked:

About an agent who took a sum of his master’s money and bought slaves with it. He was asked, “Why are you taking your master’s money and buying slaves with it?” He replied, “I am buying them for him, and they remain his property; then I shall free them all.” When emancipating them, he claimed that they were his own slaves. He is now unable to repay their purchase price. Is the emancipation valid?

He replied:

If he bought slaves for the man with his permission, then they belong to that man. If he emancipated them without their owner’s permission, his emancipation of them is invalid. If he bought them with the man’s money without his permission, the owner of the money may take possession of them, or he may require the man who misappropriated his money to repay it. If this purchaser emancipates them, the owner of the money may take possession of them, and the emancipation is void. And Allah knows best.