What did 'Ammar do when he was in a detachment and became Junub, according to what Prophet Muhammad (saw) said?
 Narrated `Abdur Rahman bin Abza:                     that while he was in the company of `Umar, `Ammar said to `Umar, "We were in a detachment and became Junub and I blew the dust off my hands (performed the rolling over the earth and prayed.)"