Messenger of Allah ﷺ said, "While I was sleeping, I saw myself drinking (i.e. milk), and I was so contented that I saw the milk flowing through my nails. Then I gave (the milk) to ʿUmar." They (i.e. the companions of the Prophet) asked, "What do you interpret it?" He said, "Knowledge."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ بَيْنَا أَنَا نَائِمٌ شَرِبْتُ يَعْنِي اللَّبَنَ حَتَّى أَنْظُرُ إِلَى الرِّيِّ يَجْرِي فِي ظُفُرِي أَوْ فِي أَظْفَارِي ثُمَّ نَاوَلْتُ عُمَرَ فَقَالُوا فَمَا أَوَّلْتَهُ قَالَ الْعِلْمَ