All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Every Muslim has to respect and hold the Prophet Muhammad in high esteem. Likewise, he has to honor all the Prophets and believe in their infallibility. One has to believe that they are chosen personalities; Allaah The Almighty protected them from every abominable act and deed. This is a generally accepted fact, no one disagrees with it except Jews who accuse the prophets of bad deeds and atheists who do not respect Allaah The Almighty and His prophets and who do not recognize their rights. After believing in this well-known and well-established fact, if one comes across any report that is contrary to the above fact, it should not make one doubtful, as either it is a fabricated story or it is to be interpreted in a way that befits the honorable status of the Prophet .
Know that Umm al-Mumineen Safiyyah daughter of Huyay was married to Salaam bin Mushkam and then Kinanah bin Al-Rabee' bin Abu al-Haqaiqh married her. Her father Huyay had been killed in the Battle of Quraizah for breaching the covenant, he was not killed in the Battle of Khaibar. The Prophet made peace with the people of Khaibar after besieging them. After that agreement, no one was killed except two persons: two sons of Abu al-Haqeeq for breaching the agreement. According to the agreement no one would hide their property, nevertheless the two sons of Abu al-Haqeeq hid the property of Huyay bin Akhtab. Thus, they were killed as a punishment.
The general rule is that the women of warriors become captives. Dihyah a Companion of the Prophet asked the Prophet to give him a slave woman and he permitted him to take one of the captives. Thus, he chose Safiyyah . Then, the Prophet was told that she was the first lady among Banu Quraythah and an-Nadheer (two Jewish tribes) and it was not suitable to make her marry anybody except him. Thereafter, the Prophet presented Islam to her, and she accepted it willingly. Then the Prophet manumitted her and married her and her Mahr (bridal dowry) was her manumission. She accepted Islam of her own free will, although it was possible for her to remain on her religion.
In fact, her manumission was an honor for her granted by the Prophet Muhammad . Indeed, her marriage with the Prophet was a blessing of Allaah The Almighty who honored her by this marriage; due to this marriage she became the Mother of all Believers. All Muslims seek Allaah's blessings for her until the Day of Judgment. Let's assume that the honor and dignity came to her after facing calamities and trials, many times favors come after a calamity as Allaah The Almighty Says (what means): {… and it may be that you dislike a thing which is good for you …}[Quran, 2: 216]
In addition, there are many narrations proving that the Prophet brought peace and happiness to her and comforted her. He also clarified the reasons for what had happened to her people. Thereupon she said, "I did not get up from my place until he was the most beloved person to me". Another narration reads that she said, "I never saw anyone who has a better character than the Prophet ". She also said, "I saw him riding on his mount while I was feeling sleepy and my head was falling on the stick of the mount, then he would pat me with his hand saying: "Take it easy, O daughter of Huyay bin Akhtab" . When they reached Al-Sahabah he said to her: “O Safiyyah! I apologize for what I did to your people; certainly they accused me of such and such."
In fact, Allaah The Almighty honored His Prophet by protecting him from marrying any woman who hated or disliked him. On the other hand, Allaah The Almighty prepared her mentally for this marriage wherein she had seen in a dream that a full moon fell in her lap. When she narrated this dream to her husband Kinaanah, he slapped her saying, 'Do you like the king of Yathrib'? Afterwards, the Prophet noticed the green discoloration around her eyes due to that slap. Very soon, she knew that Allaah The Almighty made her dream come true and honored her by her marriage with His beloved Prophet . She died during the caliphate of Mu'aawiyah in 50 A.H. Indeed, she is the wife of the Prophet in both this world and the Hereafter.
Allaah Knows best.