[Abu 'Eisa said:] This Hadith is Hasan Sahih, meaning both of the Ahadith are Sahih. Some of his Companions pledged to him for death, they said only: "We will not leave from in front of you as long as we are not killed." While others pledged him by saying: "We will not flee."
In-book : Book 21, Hadith 56
English translation : Vol. 3, Book 19, Hadith 1594