Sulayman said: The cause of the Islam of Qubath bin Ashyam al-Laythi (may Allah be pleased with him) was that some people from his tribe and from other Arab tribes came to him and said: "Muhammad bin Abd al-Muttalib has come out calling to a religion different from our religion." So Qubath (may Allah be pleased with him) got up and came to the Messenger of Allah (peace and blessings be upon him). When he entered upon him (peace and blessings be upon him), he (peace and blessings be upon him) said to him: "Sit down, O Qubath!" Qubath was startled, and the Messenger of Allah (peace and blessings be upon him) said to him: "Are you the one who said: If the women of Quraysh had come out with their sleeves, they would have driven back Muhammad and his companions?" Qubath said: "By the One who sent you with the truth, my tongue never moved with it, nor did my lips utter it, nor did anyone hear it from me; it was only a thought that occurred in my heart. I bear witness that there is no true god except Allah, alone, with no partner, and I bear witness that Muhammad (peace and blessings be upon him) is the Messenger of Allah." (And) he said: "And indeed what you have brought is the truth."
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 16122