Musnad Ahmad 27:1943

Uthman ibn Umar narrated to us, Yunus informed us, from al-Zuhri, from Salim ibn Abdullah, from Ibn Umar, that the Messenger of Allah (may Allah bless him and grant him peace) said: "There is no envy except in two: A man whom Allah the Exalted has given this Book, so he stands with it during the hours of the night and the hours of the day; and a man whom Allah the Exalted has given wealth, so he gives charity from it during the hours of the night and the hours of the day."