Abdullah bin Umar reported,

I heard the Messenger of Allah ﷺ say, "While I was asleep, I was brought a cup of milk and I drank from it until I could see the satisfaction flowing out through my fingernails. Then I gave what was left to Umar bin Khattab."They asked, "How did you interpret it, Messenger of Allah?"He replied, "Knowledge."

Azami 9866

Sahih

عن عبد الله بن عمر قال

سمعت رسول الله ﷺ قال: بينما أنا نائم أتيت بقدح لبن، فشربت حتى أني لأرى الري يخرج في أظفاري، ثم أعطيت فضلي عمر بن الخطاب، قالوا: فما أولته يا رسول الله؟ قال: العلم.

الأعظمي 9866صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Virtues of the Companions and reports about them
Chapter
Virtues and reports of Umar bin Khattab
Section
Abundance of knowledge of Umar bin Khattab
Numbering
Jami al-Kamil 9866 (2nd edition)
Azami 9866