From his father, from his grandfather, that the Messenger of Allah (ﷺ) said during his Khutbah: "Fulfill the allegiances sworn in Jahiliyyah for it" - meaning Islam - "does not add to them except in gravity. And do not initiate new allegiances in Islam." [He said:] There are narration on this topic from 'Abdur-Rahman bin 'Awf, Umm Salamah, Jubair bin Mut'im, Abu Hurairah, Ibn 'Abbas, and Qais bin 'Asim. [Abu 'Eisa said:] This Hadith is Hasan Sahih.
حَدَّثَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، حَدَّثَنَا حُسَيْنٌ الْمُعَلِّمُ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ فِي خُطْبَتِهِ أَوْفُوا بِحِلْفِ الْجَاهِلِيَّةِ فَإِنَّهُ لاَ يَزِيدُهُ يَعْنِي الإِسْلاَمَ إِلاَّ شِدَّةً وَلاَ تُحْدِثُوا حِلْفًا فِي الإِسْلاَمِ . قَالَ وَفِي الْبَابِ عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ وَأُمِّ سَلَمَةَ وَجُبَيْرِ بْنِ مُطْعِمٍ وَأَبِي هُرَيْرَةَ وَابْنِ عَبَّاسٍ وَقَيْسِ بْنِ عَاصِمٍ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
Tirmizi
The Book on Military Expeditions • Hadith 1629