Sunan Ibn Majah, Chapter: The Chapters on Shares of Inheritance

that Umar bin Khattab stood up to deliver a sermon one Friday, or he addressed them one Friday. He praised and glorified Allah, and said: "By Allah, I am not leaving behind any problem more difficult than the one who leaves behind an heir. I asked the Messenger of Allah (saw), and he never spoke so harshly to me about anything as he spoke to me about this. He jabbed his finger into my side or my chest and said: 'O Umar, sufficient for you is the Verse that was revealed in summer, at the end of Surat An-Nisa'." Sahih