Anas bin Malik narrated that Abu Bakr Siddiq 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 P.B.U.H enjoined upon the Muslims as Allah commanded the Messenger of Allah P.B.U.H The ages of camels to be given (in Zakat) may be made up in sheep. S0 if a man has camels on which the Sadaqah is a [adhaan (a four-year-old shecamel), and he does not have a Jadha'ah 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)