But it is this statement I want to call out:
R. Joshua b. Levi stated: What [is the implication of] what was written: (You shall therefore keep the commandments, and the statutes, and the judgments,) which I command thee this day, to do them? (Deut. 7:11)
‘This day [you are] to do them’ but you cannot postpone doing them for tomorrow; (i.e. after death)
‘this day [you are in a position] to do them’ and tomorrow [is reserved] for receiving reward for [doing] them.
Why does the text bother to include the unnecessary “this day”? To remind us that mitzvot cannot be performed after death – it is our responsibility to do them now. And the reward, according to this view, is not in this world but in the World to Come.
Just do it.