Volume 4, Book 55, Number 606:
Narrated Malik bin Sasaa:
Allah’s Apostle 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 said, “Gab –
riel greeted and so did I, and he returned the greeting saying, ‘Welcome, O Pious Brother and Pious
Prophet.”