Musannaf Ibn Abi Shaybah

Hazrat Ali (may Allah be pleased with him) was asked: If a man buys a slave woman and has children with her, and then someone establishes testimony that this slave woman belongs to him, what is the ruling? He replied: The slave woman will be returned to him, the value of the child of the slave woman will be assessed, and a penalty will be taken from the one who sold the slave woman.

Ibrahim says that if a man saw his slave-girl with another man, that man bought his slave-girl and had children from her, then he (the original owner) will take back the slave-girl and will take the price of the children from the father of the children.

Hazrat Maisarah says that for every servant, there is a servant in return.

Hasan says that for every servant, there is a servant in return.

Hazrat Salim says that I asked Hazrat Sha'bi, "From when will the value of a boy be determined?" He replied, "From the day he is born."