Jami` at-Tirmidhi 1592
جامع الترمذي#1592SahihNarrated Yazid bin Abi 'Ubaid: "I said to Salamah bin Al-Akwa': "For what did you pledge to the Messenger of Allah (ﷺ) on the Day of Al-Hudaibiyyah?" He said: "For death." This Hadith is Hasan Sahih
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Bashar Awad MaaroufHasan Sahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 21:54