Anas bin Malik (RA) narrated that Abu Bakr Siddiq (RA) wrote to him: "In the Name of Allah, the Most Gracious, the Most Merciful. This is the obligation of Sadaqah which the Messenger of Allah ﷺ enjoined upon the Muslims as Allah commanded the Messenger of Allah ﷺ The ages of camels to be given (in Zakat) may be made up in sheep. So if a man has camels on which the Sadaqah is a [adhaan (a four-year-old shecamel), and he does not have a Jadhaah but he has a Hiqqah (a three-year-old she-camel), then the Hiqqah should be accepted from him, and two sheep should be given (in addition), if they are readily available, or twenty Dirham. If a man has camels on which the Sadaqah is a Hiqqah, and he only has a Bint Labun (a two year-old she-camel), then the Bint Labun should be accepted from him, along with two sheep or twenty Dirhams. If a man has camels on which the Sadaqah is a Bini Labun, and he does not have one, but he has a Hiqqah, then it should be accepted from him, and the Zakfit collector should give him back twenty Dirham or two sheep. If a man has camels on which the Sadaqah is a Bini Labun, and he does not have one, but he has a Bini Makhdd (a one-year-old she-camel), then the Bini Makhad should be accepted from him, along with twenty Dirham or two sheep. If a man has camels on which the Sadaqah is a Bini Makhad, and he does not have one, but he has a Bini Labun, then the Bini Labun should be accepted from him, and the Zakat collector should give him back twenty Dirhams or two sheep. Whoever does not have a Bini Makhad, but he has a Bin Labun (a two-yearold male camel), then it should be accepted from him and nothing else need be given along with it." (Sahih)