The Prophet’s ﷺ envoy to Bosra had been killed on Byzantine-allied ground. Three thousand men were sent north 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 that the Byzantines and their Ghassanid allies were massing at Masharif in numbers nobody had expected. The men debated turning back and sending to Madinah for instructions.
ʿAbdullah ibn Rawahah ﵁ ended it: they had not come out for numbers, but for the thing they were promised. They went on.