Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said that if a person mortgages a garden for a fixed period, then the fruits that had appeared in the garden before the mortgage will not be included in the mortgage, except in the case where the mortgagee has stipulated it, then those fruits will also be included in the mortgage. And if someone mortgages a pregnant slave woman, or if she becomes pregnant after being mortgaged, then her child will also be included in the mortgage with her. This is the difference between fruits and children, because fruits are not included even in a sale. The Messenger of Allah, peace and blessings be upon him, said: "Whoever sells date-palm trees, the fruits will belong to the seller, except when the buyer stipulates otherwise."

Imam Malik, may Allah have mercy on him, said that in our view there is no difference of opinion in this: if someone sells a slave woman or an animal and she is pregnant, then the child will belong to the buyer, whether the buyer stipulates it or not. So, a date-palm tree is not like an animal, nor are the fruits like the offspring of a date-palm.

Imam Malik, may Allah have mercy on him, said that this is also evidence that a person can mortgage the fruits of trees without the trees themselves, but it is not possible to mortgage the unborn child without its mother, whether it is a human or an animal.