Musannaf Ibn Abi Shayba 26:435

Hussain bin Ali narrated to us, from Za'idah, from Simak, from Hanash, who said: A man had intercourse with a slave girl, then he sold her to another man, and he (the second man) had intercourse with her. They both had intercourse with her during the same period of purity (tuhr), and she gave birth to a boy. They came to Ali, and Ali said: You have both left (the matter) and it is not for his mother, and he belongs to the remainder of you (the one who is left) in the status of his mother.