Al-Bara' reported that a person was reciting Surat al-Kahf and there was a horse tied with two ropes at his side, a cloud overshadowed him, and as it began to come nearer and nearer his horse began to take fright from it. He went and mentioned that to the Prophet (ﷺ) in the morning, and he (the Holy Prophet) said: That was tranquility which came down at the recitation of the Qur'an.
Shaykh Maulana Abdul Aziz Alvi
Hadith Commentary: Vocabulary of the Hadith: Shatan: It refers to a long and extended rope, which is used to tie a horse.
Benefits and Issues: Sakinah refers to tranquility of the heart and inner peace, which is the result of Allah Ta'ala's grace and mercy. The recitation of the Qur'an is a means of Allah Ta'ala's mercy, and in this hadith, it has been described in a particular form. For this reason, Imam Nawawi rahimahullah has written that Sakinah is one of the creations of Allah Ta'ala, which becomes a cause of serenity and mercy, and along with it are angels.
Source: Tuhfat al-Muslim: Commentary on Sahih Muslim, Page: 1856
´Jabir said:` "We did not give our pledge to the Messenger of Allah for death, rather we pledged not to flee (from battle)."
Hafiz Muhammad Ameen
The meaning of pledging allegiance unto death is also this: that we will remain steadfast and will not flee, even if circumstances of death arise. The intent of Hazrat Jabir radi Allahu anhu is that, at the time of pledging allegiance, we did not say, "even if we die." We only said that we will not flee. However, in meaning and outcome, there is no difference. Some people have also used the word "death," saying that we will not flee, even if death comes, as is explicitly stated in the following narration.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 4163