What is the concept of legitimate viewing (al-ru'yah al-shar'iyyah), and is it permissible for a suitor to see the hair of his fiancée?

The Islamic legal perspective on seeing the fiancée means the suitor looking at what he desires in her for marriage, based on the Prophet, peace and blessings be upon him, saying: "If one of you proposes to a woman, and he is able to look at what encourages him to marry her, then let him do so." Scholars have differed on what is permissible for the suitor to see. The majority of scholars are of the opinion that it is permissible to see only the face and hands. Some scholars, such as the Hanbalis, mentioned the permissibility of seeing the fiancée's hair. There are other views among the Hanbalis that permit looking at what commonly appears, such as the neck, hands, and feet, or even anything other than the major 'awrah.