Al-Miswar bin Makhramah and Marwan bin al-Hakam (may Allah be pleased with them both) mentioned the hadith of the Treaty of Hudaybiyah, and in it mentioned the story of Abu Jandal (may Allah be pleased with him) and Abu Basir (may Allah be pleased with him), and it is more complete than this.
The Shaykh says: The Prophet (peace and blessings be upon him) returned Abu Jandal (may Allah be pleased with him) only because, owing to his father's standing, he (peace and blessings be upon him) did not fear for him in returning him; and for the same reason he advised Abu Basir (may Allah be pleased with him) at first to go back, and Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18427