Imām Bukhārī narrates: Muhammad ibn al-'Alā' narrated to us, he said: Abū Usāmah informed us, from Buraid, from Abī Burdah, from Abū Mūsā, may Allāh be pleased with him, he narrates that:
I and my companions who came with me in the boat landed in the open plain of Bathān, and the Prophet ﷺ was in Madīnah. So every night, a group among them would come by turns to the Prophet ﷺ for the 'Ishā' prayer. So one day it happened to us: I and my companions went to the Prophet ﷺ, and he was engaged in some task at home. He delayed the prayer until it became midnight. Then the Prophet ﷺ came out, so he led them in prayer. So when he finished the prayer, he said to those present: Wait! Hear glad tidings! Among the blessings of Allāh the Exalted upon you is this: that at this time, no one else besides you is praying — or he said: at this time, no one else besides you has prayed. We do not remember which of these two things he said. Abū Mūsā said: We returned happily after hearing this from the Messenger of Allāh ﷺ.
Reference: Sahih Al Bukhari 567