Musannaf Ibn Abi Shaybah 18988 — A man with several wives who says

Ibrahim (may Allah have mercy on him) said: If a man has three wives and he says, "His wife is divorced," then if he intended one of them, it is she whom he intended who is divorced; and if he did not intend any of them, he may choose whichever of them he wishes. The same ruling applies to ila' and zihar.