I heard Messenger of Allah ﷺ saying, "While I was sleeping, I saw a bowl full of milk was brought to me and I drank of it (to my fill) till I noticed its wetness flowing (in my body). Then I gave the remaining of it to ʿUmar." They asked, "O Messenger of Allah ﷺ! What have you interpreted (about the dream)? He said, "(It is Religious) knowledge." (See Hadith No. 134)  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ بَيْنَا أَنَا نَائِمٌ أُتِيتُ بِقَدَحِ لَبَنٍ فَشَرِبْتُ مِنْهُ حَتَّى إِنِّي لأَرَى الرِّيَّ يَجْرِي ثُمَّ أَعْطَيْتُ فَضْلَهُ عُمَرَ قَالُوا فَمَا أَوَّلْتَهُ يَا رَسُولَ اللَّهِ قَالَ الْعِلْمُ