Messenger of Allah ﷺ talked to his companions about his Night Journey to the Heavens. When he reached the fifth Heaven, he met Aaron. (Gabriel said to the Prophet), "This is Aaron." The Prophet ﷺ said, "Gabriel greeted and so did I, and he returned the greeting saying, 'Welcome, O Pious Brother and Pious Prophet."
أَنَّ رَسُولَ اللَّهِ ﷺ حَدَّثَهُمْ عَنْ لَيْلَةِ أُسْرِيَ بِهِ حَتَّى أَتَى السَّمَاءَ الْخَامِسَةَ فَإِذَا هَارُونُ قَالَ هَذَا هَارُونُ فَسَلِّمْ عَلَيْهِ فَسَلَّمْتُ عَلَيْهِ فَرَدَّ ثُمَّ قَالَ مَرْحَبًا بِالأَخِ الصَّالِحِ وَالنَّبِيِّ الصَّالِحِ