The Prophet ﷺ said, "A prophet's eyes sleep, but his heart does not sleep."
قال النبي ﷺ: النبي تنام عيناه، ولا ينام قبله.
Imam Ahmad narrated it (2514) from Hashim bin Qasim, who said, Abdul-Hameed narrated to us, who said, Shahr narrated to us, who said, Ibn Abbas said... and he related the hadith at length. It has already been mentioned in the chapter on belief in the angels. There is some discussion regarding Shahr, but he has been corroborated by other narrators.