On Lag Baomer, we joyfully sing: "Omar R‘ Akiva, Ashreichem Yisrael! Ma hamikva metaher es hat’meim kach Hkb’h metaher es yisroel.“ Why was it necessary for R’ Akiva to tell us this?
The Lubavitcher Rebbe explains: As we know, there are no extra words in Mishnayos. Therefore, it may seem strange for R’ Akiva so specify: “Ma mikva metaher - es Hat’meyim.” Isn’t it obvious that a mikva is metaher tmeyim?? He should have said “Ma hamikva metaher – kach Hkb’h metaher..!?”
The gemara has a dispute: If someone becomes tomei by touching a sheretz or by seeing shichvas zera, he must go to the mikva – and when night falls, he’s tahor. If someone, however, touches a 'mess' (corpse), he must go through a seven-day procedure that includes getting sprinkled with the ashes of the Poroh Aduma, only then he regains his tahara.
Here comes the question: What if someone who touched a corpse during the 7 days of purity touches a sheretz or sees shichvas zerah? Do we say “let him take care of the small tumah and then you can proceed “ or do we say “You anyways are impure, so what difference does this small impurity make? Plus: The greater impurity will be removed thru the ashes of the porah adumah – so why make an effort for something that will vanish anyway?”
R’ Akiva viewed the first opinion as correct and sent us a message: Of course, a mikva makes a person tahor! However, “Ma hamikva metaher es hatmeyim” – just like a mikva is metaher the tmeyim (even though he is possessed by a much greater tuma, as above) - “Kach Hkb’h metaher es yisrael” - So too, we still may be deep in the mud, but even a small step towards Hashem is very valued by Him and will purify us. Often, it doesn’t seem to make sense to make a small change, feeling that it is so insignificant and that greater action is needed for any result. R’ Akiva teaches us that every small action is productive!