I heard that the Bet HaLevi and the Peri Megadim hold that there is no Mitzva for a person to don Tefilin everyday. Can someone source these opinions and explain exactly what they are meaning to say?
I always understood that they mean to say that the mitzva is to have them on always and there is no difference if you wear it for 1 hour today and 1 hour tomorrow or two hours today and none tomorrow. Each second is its own individual mitzva independent of what day it is on. It is actually kind of hard to justify why each date should matter.