Musannaf Ibn Abi Shayba 27:139

Abu Usama narrated to us, from Ibn 'Awn, from Umayr ibn Ishaq, who said: When the Prophet, peace and blessings of Allah be upon him, and Abu Bakr set out for Medina, Suraqa ibn Malik followed them. When he saw them, he said: "These are the fugitives of Quraysh. If I were to return their fugitives to Quraysh [it would be a great deed]." He said: So he spurred his horse toward them. He said: Then the horse sank [into the ground]. He said: "Pray to Allah to bring it out, and I will not approach you both." He said: So it came out. He then returned [to pursue them] until he did that two or three times. He said: Then he said: "Do you want provisions and a mount?" They said: "We do not want [that], and we have no need for that. Spare us yourself." He said: "I have spared you."