Ibn Umar (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) separated a husband and wife from Banu Ajlan, and did so by joining his index and middle fingers together and then separating them, explaining the matter through this gesture. And he said: "Allah Almighty knows that one of you is lying. So, will any of you repent?"
Hadith Referenceمسند الإمام الشافعي / كتاب اللعان / 1344