Musannaf Ibn Abi Shaybah

Hazrat Saeed bin Musayyib (may Allah have mercy on him) says that there is no harm if a person works in a tree (date palm), and fixes a third or a quarter, as long as he does not spend anything from it.

Hazrat Hasan (may Allah be pleased with him) disliked it unless the wage was fixed and known.

Hazrat Salim, may Allah have mercy on him, says regarding deeds in the tree: Whoever acts within it will be given from it.

Ibrahim (may Allah have mercy on him) disliked every matter in which a third or a quarter of the deed was fixed.

Hazrat Zuhri (may Allah have mercy on him) says that if a laborer works for one-third or one-fourth of the wage, there is no harm in it.

Hazrat Hammad (may Allah have mercy on him) says: If a laborer is employed in such a way that he is told, "Whatever produce is obtained from the land, a third or a quarter of it will be given to me," this is disliked (makrooh).