When Mecca was conquered for the Messenger of Allah ﷺ, he delivered a long sermon, in which he said, "Honor the alliances made in the days of ignorance, for Islam only adds strength to them. But do not form new alliances under Islam."
لما فتح على رسول الله ﷺ مكة قال: فذكر الخطبة بطولها وجاء فيها: وأوفوا بحلف الجاهلية فإن الإسلام لم يزده إلا شدة، ولا تحدثوا حلفا في الإسلام.
Ahmad (6933) and Tirmidhi (1585) both narrated it through Yazid, who said, Husayn Muallim informed us, from Amr bin Shuayb, from his father, from his grandfather, who said, and then he related the hadith. Its chain is hasan because of Amr bin Shuayb, for he is hasan al-hadith. Tirmidhi said, "hasan sahih."In the same meaning, it was also narrated from Qays bin Asim that he asked the Prophet ﷺ about oaths of alliance, and he said, "Whatever alliance existed in the pre-Islamic era, hold fast to it, but there is no new alliance in Islam." Ahmad (20613, 20614), Tabarani (33718), and Bazzar in Kashf Astar (1915) narrated it, and Ibn Hibban (4396) graded it sahih, all of them through the hadith of Mughira, from his father, from Shuba bin Tawam, from Qays bin Asim, and then he related the hadith.Abu Mughira is Miqsam Dabbi, from whom no one narrated except his son Mughira. This is how Ibn Abu Hatim mentioned him in Jarh Tadil, and Ibn Hibban in his Thiqat, so he falls among the unknown narrators. Likewise, in the chain is Shuba bin Tawam, from whom Miqsam Dabbi, Haytham bin Zayd, and others narrated, but no one deemed him reliable except Ibn Hibban. Bukhari said, "Shuba bin Tawam said, We came to Ibn Masud in the time of Umar." This is how it is mentioned in Tajil.As for what Ibn Hajar said in Ithaf (14/730), after attributing it to Ibn Hibban, "its apparent form is mursal," this is indeed as he said, for he said in it, "from Shuba bin Tawam, that Qays bin Asim asked the Prophet ﷺ," so it seems that Shuba did not hear it directly from Qays.