Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said: If someone makes a musaqat contract for land in which there are trees—either grapevines or date palms—and there is also some empty land, then if the empty land is one-third or less, the musaqat is valid. But if the empty land is more and the trees are in one-third or less, then it is permissible to rent out such land, but musaqat is not valid. This is because it is the custom of people that they make musaqat contracts for land, and a small portion of the land remains empty, or they rent it out and a small portion of the land contains trees. Or, for example, a mushaf or a sword that has silver on it is sold in exchange for silver, or a necklace or ring that contains gold is sold in exchange for gold. And people have always conducted such transactions. No specific limit has been set that if the amount of gold or silver is up to a certain extent, it is lawful, and if it is more, it is unlawful. However, according to us, in accordance with the practice of the people, the ruling is that when the gold or silver in a mushaf, sword, or ring is equal to one-third of the price or less, then its sale in exchange for silver or gold is valid; otherwise, it is not valid.