Sulaiman bin al-Mughira al-Qaysy سليمان بن المغيرة القيسي مولاهم · The Book on Zakat

"We used to hope that an intelligent Bedouin would show up to question the Prophet while we were with him. So one while we were with him, a Bedouin came, kneeling in front of the Prophet, and he said: 'O Muhammad, your messenger came to us and told us that you say that Allah sent you.' So the Prophet say: 'Yes.' He said, 'So, (swear) by the One who raised the heaves, and spread out the earth, and erected the…