Sahih al-Bukhari, Volume 9, Book 87, Hadith 134 (USC-MSA) ⓘ

Narrated Ibn `Umar: I heard Allah's Messenger saying, "While I was sleeping, I was given a bowl full of milk (in a dream), and I drank of it to my fill until I noticed its wetness coming out of my nails, and then I gave the rest of it to `Umar." They (the people) asked, "What have you interpreted (about the dream)? O Allah's Apostle?" He said, "(It is Religious) knowledge."

حَدَّثَنَا عَبْدَانُ، أَخْبَرَنَا عَبْدُ اللَّهِ، أَخْبَرَنَا يُونُسُ، عَنِ الزُّهْرِيِّ، أَخْبَرَنِي حَمْزَةُ بْنُ عَبْدِ اللَّهِ، أَنَّ ابْنَ عُمَرَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ بَيْنَا أَنَا نَائِمٌ أُتِيتُ بِقَدَحِ لَبَنٍ، فَشَرِبْتُ مِنْهُ، حَتَّى إِنِّي لأَرَى الرِّيَّ يَخْرُجُ مِنْ أَظْفَارِي، ثُمَّ أَعْطَيْتُ فَضْلِي ‏"‏‏.‏ يَعْنِي عُمَرَ‏.‏ قَالُوا فَمَا أَوَّلْتَهُ يَا رَسُولَ اللَّهِ قَالَ ‏"‏ الْعِلْمَ ‏"‏‏.‏