The Meaning of the Preposition "ba" in the Phrase "And Wipe Your Heads"

Question:
In the first view, what is meant by the jurists' statement that the "ba" in the phrase "or they bewitched your heads" indicates the shared portion? This is the view of those who hold that wiping part of the head is sufficient.

Answer:
Allah (Exalted and Majestic is He) says, "And wipe your heads." When "head" is used in a general sense, it encompasses the entire head, and part of it is not sufficient, just as Allah the Exalted said: regarding Hajj and 'Umrah. If a person shaves part of his head during Hajj or 'Umrah, it is not permissible, because if he shaves only part of his head, it is not accepted by all scholars. Likewise, shortening the hair must encompass the entire head. Therefore, when "head" is used in a general sense, it includes the whole of it.