Sahih Muslim Book - 44, Hadith - 6190

حَدَّثَنِي حَرْمَلَةُ بْنُ يَحْيَى ، أَخْبَرَنَا ابْنُ وَهْبٍ ، أَخْبَرَنِي يُونُسُ ، أَنَّ ابْنَ شِهَابٍ ، أَخْبَرَهُ عَنْ حَمْزَةَ بْنِ عَبْدِ اللهِ بْنِ عُمَرَ بْنِ الْخَطَّابِ ، عَنْ أَبِيهِ ، عَنْ رَسُولِ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، قَالَ : بَيْنَا أَنَا نَائِمٌ ، إِذْ رَأَيْتُ قَدَحًا أُتِيتُ بِهِ فِيهِ لَبَنٌ ، فَشَرِبْتُ مِنْهُ حَتَّى إِنِّي لأَرَى الرِّيَّ يَجْرِي فِي أَظْفَارِي ، ثُمَّ أَعْطَيْتُ فَضْلِي عُمَرَ بْنَ الْخَطَّابِ قَالُوا : فَمَا أَوَّلْتَ ذَلِكَ ؟ يَا رَسُولَ اللهِ ، قَالَ : الْعِلْمَ.

It was narrated from Hamzah bin 'Abdullah bin 'Umar bin Al-Khattab from his father that the Messenger of Allah (s.a.w) said: 'While I was sleeping, I saw a vessel that was brought to me, in which was milk. I drank from it until its moisture flowed from beneath my nails, then I gave my leftovers to 'Umar bin Al-Khattab.' They said: 'How did you interpret that, O Messenger of Allah?' He said: 'Knowledge.'"