Musannaf Ibn Abi Shaybah

Ibrahim, Hazrat Ibn Sirin, and Hazrat Ata—all these respected scholars—regarding the person who harms the child in a woman's womb, stated as follows: Indeed, it is obligatory upon that person to both pay the blood money (ghurra) and to free a slave.

Hazrat Sha’bah states that I heard Hazrat Hakam saying that when someone strikes a woman causing her to miscarry her child, the one who struck must free a slave.

Hazrat Umar bin Zar states that Hazrat Mujahid said: When a woman struck another woman on the abdomen causing her to miscarry, Hazrat Umar ordered that the woman (who struck) should free a slave.