Nasai

(1) "They fell into prostration"—that is, some among them who were Muslims, but whose Islam was not known to others, used prostration as a means to express their Islam. However, in the chaos of battle, this was not noticed and they too were killed. In this, the slain themselves were at fault for living among the polytheists (mushrikin); therefore, the Prophet (sallallahu alayhi wa sallam) paid half of their blood money (diyah). And then he gave a warning that Muslims and polytheists should not live together, especially in such a state where there is no distinction between them. Rather, Muslims should keep such a distance from the polytheists that even each other's fire is not visible. In other words, they should live in separate settlements. The population of Muslims should be separate and that of the disbelievers (kuffar) separate, so that in case of an attack, distinction can be made.

(2) This narration has no connection with the chapter, but it is related to the book in that if a Muslim is killed out of ignorance or by mistake, his blood money (diyah) must be paid. And Allah knows best!

(3) When a person expresses his Islam, then it is forbidden to kill him, even if he continues to live among the disbelievers.

(4) Without necessity, it is not permissible to reside in the land of war (dar al-harb). Especially, to take up permanent residence there is absolutely not allowed.

(5) Although the verifier of the book has declared this narration weak in its chain (isnad), other scholars have discussed it in detail and, based on other supporting evidences, have declared it authentic (sahih). And in light of the proofs, their position appears to be stronger. See: (Irwa’ al-Ghalil: 5/29-33, and Dhakheerat al-‘Uqba Sharh Sunan al-Nasa’i: 36/114-118)

(6) For further benefits and issues, see: (Sunan Abi Dawud, translated, Darussalam edition, Hadith: 2645)