Musnad Ahmad 57:1

Waki’ narrated to us, Zakariya ibn Ishaq narrated to us, from ‘Amr ibn Abi Sufyan, who heard it from him from Muslim ibn Thafana, who said: Ibn ‘Alqama appointed my father as the collector of his people’s alms (sadaqah), and he ordered him to collect their alms. He said: My father sent me with a group to bring him their alms. He said: I went out until I came to an old man called Sa’r. I said: "My father sent me to you so that you may pay the alms of your sheep." He said: "O son of my brother, which ones do you choose?" I said: "We choose until we even measure the udders of the sheep." He said: "O son of my brother, I will tell you that I was in one of these mountain passes with my sheep during the time of the Prophet, may Allah bless him and grant him peace. Two men came to me on a camel and said: 'We are the messengers of the Prophet, may Allah bless him and grant him peace, to you, so that you may pay the alms of your sheep.' I said: 'What is due from me regarding them?' They said: 'A sheep.'" He said: "I went to a sheep, the location of which I knew, full of milk and fat, and I brought it out to them. They said: 'This is a pregnant sheep (shafi’) that is not currently lactating (ha’il), and the Messenger of Allah, may Allah bless him and grant him peace, has forbidden us to take a pregnant sheep.' I said: 'Then what?' They said: 'A young female goat (’anaq) that is a year old (jadha’ah), or a two-year-old (thaniyyah).'" He said: "I went to a young female goat that was 'mu’tat'—he said: 'The mu’tat is one that has not given birth, but its time for giving birth has arrived'—and I brought it out to them. They said: 'Hand it to us.' I handed it to them, and they placed it with them on their camel, then they departed." ‘Abdullah said: I heard my father say: Waki’ said it like this: "Muslim ibn Thafana," which is a mistake (tas-hif). Rawh said: "Ibn Shu’ba," and that is the correct one. My father said: And Bishr ibn al-Sari said: "There is no god but Allah, his children are here," meaning Muslim ibn Shu’ba.