The letter frames Islam’s conquests as miraculous, from a barefoot unarmed people

Evidence

In this way, with him in whom we trust, and in whom we believe, we went off, barefoot, naked, without equipment, strength, weapons or provisions, to fight against the largest empires, the most evidently powerful nations whose rule over other peoples was the most ruthless, that is to say: Persia and Byzantium. — John V. Tolan, Saracens, 267

Categorization

• XREF: A striking inversion of the classic Arab boast — here the conquest is redeployed as proof of divine aid precisely because the Arabs were so under-equipped, which connects to later self-image debates in Islamic historiography.