How can the verse "and wipe over your heads and your feet" be interpreted linguistically and grammatically?

The exegetes highlight two issues in the verse:

First: The obligatory amount of the head to be wiped, due to their differing views on the letter 'baa' in "biru'usikum" (with your heads) – whether it signifies attachment (ilsaq) or partiality (tab'eedh). The majority hold that it signifies attachment. Thus, Malik obligated wiping the entire head, while Al-Shafi'i obligated the minimum amount upon which wiping occurs. Abu Hanifa estimated the forelock to be a quarter of the head, based on what was narrated that the Prophet (peace be upon him) wiped his forelock.

Second: The recitation of "wa arjulakum" (and your feet) with either a nominative (raf') or genitive (jarr) ending, depending on the differing recitations.