My grandfather points out that the word telechu [you will go/walk] connotes progression, that it's not sufficient for a perosn to do the mitzvah out of habit but to use keeping the mitzvos and the chukim of the Torah as a means of ahieving an elevation of the soul and a a greater inclination to the spirutal -- on top of that which one has already accepted. And that is not possible without toiling in Torah.
So why is this term used instead of directly saying "toil in Torah study?" My grandafather says because that is the true goal of toiling in Torah study -- to be telechu, that is advancing spiritually.
Related post: http://kallahmagazine.blogspot.com/2015/10/dvar-yehudah-parsha-points-from-my.html