The Prophet (peace and blessings be upon him) said: "Once, while I was asleep, I saw a cup in which I was given milk. I drank from it until I felt as if milk was coming out from my nails. Then what I had left over was given to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him)." The Companions (may Allah be pleased with them) said: What is its interpretation? He (peace and blessings be upon him) said: "Knowledge."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13324