While many of us know that there are 613 mitzvot, (248 do's, and 365 don'ts) it is less widely known just how many mitzvot we can actively apply in our time, outside of Israel, when the Temple (Beit HaMikdash) no longer stands. For example, all the various sacrificial offerings are no longer able to be brought.

Of the 248 positive commands, only 126 are currently applicable. And of the 365 negative commands, only 243 are still applicable. So in total, nowadays, 369 mitzvot are still operative. Rabbi Isaiah Horowitz, better known after his famous work as the Shelah (an acronym for "Shnei Luchot HaBrit"), writes that the mnemonic for this number can be found in the verse, "I sleep, but my heart is awake." If you add up the numeric values of the letters in the Hebrew word for "I sleep," ישנה, the tally comes to 365. And when you add the number of letters that are in the word itself, 4, the total comes to 369. This hints to the fact that when the Jewish people are in exile, spiritually asleep, they only have 369 mitzvot to do.

Using a little bit of math, the author further points out that nowadays, therefore, there are 122 fewer positive mitzvot to observe (248-126=122), and also 122 fewer negative mitzvot to keep (365-243=122)! So in total, there are 244 fewer mitzvot in our day-to-day lives. The Shelah notes that this number, 244, is the same as the numerical value for the Hebrew word, מרד, which means to rebel. This equivalence, he remarks, alludes to the fact that it was because of our "rebelliousness" that we were exiled from our land, and that our Temple was destroyed. (May it be speedily rebuilt!)

Even among the 369 mitzvot, however, there are many that most of us will never do. For many of these commands also depend on circumstances. In other words, only in certain situations do many of these mitzvot have to be kept. To illustrate, only if a person makes a vow can he fulfill the command "not to be tardy" in keeping it. Only if he owns a house with a walk-out roof, is he obliged to put a fence around it.

In actuality, then, there are only 270 precepts that every Jew is required to observe, without any particular circumstance ever having to come about. Of these 270 mitzvot, 48 are positive precepts, and 222 are negative. Interestingly, in Sefer HaChinuch, the author, Rabbi Aaron HaLevi, points out that 270 is the numeric value of the Hebrew word for "awake," ער, in the above quoted verse, "I sleep but my heart is awake."

No Jew is ever completely asleep, says King Solomon. The heart, our spiritual core, is always wide awake. So being "sleepless in exile," we will undoubtedly merit the complete and final redemption, very, very soon!

I would like to note, however, that the Rabbis established the number of fixed, daily prayers to correspond to the number of regular, daily sacrifices that were offered in the Temple, thus offering somewhat of a substitute for the Temple service. So, too, when we study the laws governing such precepts, on a spiritual level, we get credit as if we had actually performed them. On a deeper level, Chassidut explains that all the precepts are operative even nowadays. For example, by not capitulating to the demands of our "animal soul," our base instincts, we offer the "animal" within ourselves to G‑d.

Rabbi Eliezer Danzinger for Chabad.org