Musa bin Talha narrates from Mu'adh bin Jabal (may Allah be pleased with him): The Prophet Muhammad (peace and blessings be upon him) said: "For land that is irrigated by rain, by 'ba'l' (planting a date palm near water so that the tree is watered by underground water itself), or by flowing water (such as a canal, etc.), payment of one-tenth (ushr) is obligatory. For land that is irrigated by sprinkling water (i.e., by artificial means), payment of half of one-tenth is obligatory. Payment of zakat is obligatory on dates, wheat, and grains, but it is exempted for cucumber, watermelon, apple, sugarcane, and other vegetables; the Prophet Muhammad (peace and blessings be upon him) has exempted it."