It is narrated from Sayyiduna Umar (may Allah be pleased with him) that I never asked the Prophet (peace and blessings be upon him) about anything more than I asked about "kalalah," until once the Prophet (peace and blessings be upon him) placed his finger on my chest and said: "The last verse of Surah An-Nisa, which was revealed in the summer, is sufficient for you."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 179