Amr bin Shu'aib narrates from his father, who narrates from his grandfather, that the Prophet Muhammad (peace be upon him) said: "When a woman claims that her husband has divorced her and she presents a just witness for it, the husband will be made to take an oath. If he takes the oath, the testimony of the witness will be nullified, and if he refuses (to take the oath), his refusal will be considered as the equivalent of another witness, and the divorce will be deemed valid (i.e., it will be considered to have taken place)."