Muwatta 704

A saying of Malik: if a man acquires livestock, camels, cattle or sheep, no charity is due on them until a year passes from the day he acquired them, unless he already has a herd subject to charity (five camels, thirty cows or forty sheep). If he has that threshold and then acquires more camels, cattle or sheep by purchase, gift or inheritance, he pays charity on them with his herd when it is paid, even if the year has not passed over what he acquired, and even if it was paid a day before he bought or inherited them. Malik gives as an example silver that a man pays zakat on and then buys goods with from a man who owes charity on it when he sells: the first paid it today and the second tomorrow. ¹

Belongs to the Muwatta, Book of Zakat. Source: the Muwatta. Mentions Malik ibn Anas. Built on in the chapters on zakat and minimum threshold (nisab) and lunar year (hawl).