Waẓīf denotes the lower portion of an animal’s leg. The repetition waẓīfan waẓīfan evokes the action of placing one leg after another. Atbaʿat means following one thing with another.
Fawqa mawrin muʿabbad identifies the ground underfoot. Muʿabbad here concerns a trodden, prepared path; it does not carry the religious sense of worship. Mawr concerns the desert track or surface.
The repetition works as poetic rhythm: the reader can almost hear the repeated footfalls as the animal moves.