Sahih al-Bukhari 432

It is related from 'Ikrima, "Ibn 'Abbas said to me and his son 'Ali, 'Go to Abu Sa'id and listen to some of his hadith.' We went and he was doing some work in a garden. He took his cloak and sat down, wrapping his legs with it, and then began to tell us hadiths until he reached the account of the construction of the mosque. He said, 'We were carrying one brick at a time but 'Ammar carried two. The Prophet, may Allah bless him and grant him peace, saw him and brushed the dust from him, saying, "May Allah have mercy on 'Ammar! An unjust party will kill him while he is calling them to the Garden and they are calling him to the Fire." 'Ammar said, "I seek refuge with Allah from tribulation."'" XXXI: Making use of carpenters and other craftsmen in constructing the minbar and the mosque