Ma'dan bin Abi Talhah (may Allah have mercy on him) said that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) delivered a sermon, and in it he said: I asked the Messenger of Allah (peace and blessings be upon him) about the verse of kalalah again and again, more than I asked about anything else, and he (peace and blessings be upon him) answered me just as sternly, until he (peace and blessings be upon him) struck my chest and said: "Is not the verse that was revealed in the summer, which is at the end of Surah al-Nisa, sufficient for you: 'They ask you for a ruling. Say: Allah gives you a ruling concerning kalalah' [Surah al-Nisa: 176]?" Soon I will give such a ruling concerning kalalah that both those who read and those who do not read will know it; and it (kalalah) is one who has no father, as I understand it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12270