How did the Prophet, may Allah bless him and grant him peace, marry Safiyyah bint Huyayy ibn Akhtab in the Battle of Khaybar? And are there any doubts concerning his marriage to her, such as her not observing the 'iddah (waiting period) or her husband being killed on the same day, or that the Prophet, may Allah bless him and grant him peace, took her after another Companion had chosen her for himself?

It is not permissible to believe there is any doubt concerning the actions of the Messenger of Allah, peace and blessings be upon him, for Allah protected him from the unlawful, and his actions are legislation.

The Prophet, peace and blessings be upon him, did not marry Safiyyah except after ensuring she was not pregnant, as he left her with Umm Sulaym until her waiting period (iddah) was over, as stated in the Sahihayn.

As for the Prophet's command, peace and blessings be upon him, to return Safiyyah after Dihyah had taken her, there is nothing wrong with this, because it is among the unique prerogatives of the Messenger of Allah, peace and blessings be upon him, to have the choicest share (safi) of the war booty. Moreover, Safiyyah did not fall to Dihyah's lot, and even if we were to assume that, Dihyah would have been content to give her to the Prophet, peace and blessings be upon him. Her being the daughter of the leader of her people makes the Messenger of Allah, peace and blessings be upon him, more deserving of her than anyone else.