Oh God, highest friend in heaven! - Ibn Kathir

...so that they may learn about the religion of Allah, so that Allah’s call will spread among His servants….In summary, those who come from a land at war with Muslims to the area of Islam, delivering a message, for business transactions, to negotiate a peace treaty, to pay the Jizyah, to offer an end to hostilities, and so forth, and request safe passage from Muslim leaders or their deputies, should be granted safe passage, as long as they remain in Muslim areas, until they go back to their land and sanctuary.

Also (forbidden are) women already married, except those whom your right hands possess. The Ayah means, you are prohibited from marrying women who are already married, except those whom your right hands possess, except those whom you acquire through war, for you are allowed such women after making sure they are not pregnant. Imam Ahmad recorded that Abu Sa`id Al-Khudri said, "We captured some women from the area of Awtas who were already married, and we disliked having sexual relations with them because they already had husbands. So, we asked the Prophet about this matter, and this Ayah was revealed, Also (forbidden are) women already married, except those whom your right hands possess. Consequently, we had sexual relations with these women." This is the wording collected by At-Tirmidhi An-Nasa'i, Ibn Jarir and Muslim in his Sahih.

Abu Dawud At-Tayalisi recorded that Ibn `Abbas said, "Sawdah feared that the Messenger of Allah might divorce her and she said, `O Messenger of Allah! Do not divorce me; give my day to `A'ishah.' And he did, and later on Allah sent down,And if a woman fears cruelty or desertion on her husband's part, there is no sin on them both." Ibn `Abbas said, "Whatever (legal agreement) the spouses mutually agree to is allowed." At-Tirmidhi recorded it and said, "Hasan Gharib." In the Two Sahihs, it is recorded that `A'ishah said that when Sawdah bint Zam`ah became old, she forfeited her day to `A'ishah, and the Prophet used to spend Sawdah's night with `A'ishah. There is a similar narration also collected by Al-Bukhari. Al-Bukhari also recorded that `A'ishah commented: And if a woman fears cruelty or desertion on her husband's part, that it refers to, "A man who is married to an old woman, and he does not desire her and wants to divorce her. So she says, `I forfeit my right on you.' So this Ayah was revealed."