The Prophet’s ﷺ envoy to Bosra had been killed on Byzantine-allied ground, and an envoy was protected under every convention the region recognised. Three thousand men were sent to answer it — the largest force he had yet despatched without going himself, and it was going against the frontier of an empire.
At Maʿan they learned the Byzantines and their Ghassanid allies were massing at Masharif, a few days north, in numbers nobody had expected. The column halted for two nights while the men argued about whether to go on or send to Madinah for instructions.
ʿAbdullah ibn Rawahah ﵁ ended it: they had not come out for numbers, he said, but for the thing they were promised. They went on, and moved the meeting place west to Muʾtah to pick their own ground.