1)
Why does it say "Holech v'Sak'u"?
1.
Radak: This is like "Haloch v'Sak'u." While the Me'asef walked, the Kohanim blew.
2)
Why is "Holech v'Sako'a" repeated?
1.
Malbim: They started blowing when they left Gilgal, and did not cease the entire time they walked.
