There is no biblical reference to 613 commandments, although the later rabbinic leaders claimed that all 613 commandments are alluded to within the Ten Commandments. The first actual reference to 613 commandments is found in a lengthy Talmudic passage. There, Rabbi Simlai (third century a.d.) is quoted as saying, “Six hundred and thirteen precepts were communicated to Moses, three hundred and sixty-five negative precepts, corresponding to the number of solar days [in the year], and two hundred and forty-eight positive precepts, corresponding to the number of the members of man’s body” (b. Makkot 23b–24a; we will return to this passage at the end of this answer). Based on this comment, medieval Jewish scholars sought to come to agreement as to the exact enumeration and delineation of the 613 commandments, since there is a good deal of ambiguity in counting.[87]
For example, would you count “Be fruitful and multiply,” spoken in Genesis 1:28 and repeated in Genesis 9:1 (nasb), to be one of the 613 commandments? The rabbis did, recognizing it as the first word of command given to the human race. What about commandments that overlap each other? Should these be subdivided?
Questions such as these, among many others, caused these scholars to come up with slightly different counts—there was essential agreement about the vast majority of these commandments—and the most famous compilation of all, Maimonides’ Book of the Commandments, actually counted only 606 explicit Torah commandments, the last seven consisting of rabbinic commandments, namely: (1) the command to wash the hands before eating (note the conflict over this already in Matthew 15 and Mark 7); (2) laws regarding the Eruv, a rabbinic concept that removed some Sabbath restrictions in very specific ways; (3) reciting a blessing before eating or partaking of any kind of pleasure; (4) lighting the candles on the Sabbath; (5) celebrating the holiday of Purim, which is referred to in the book of Esther but whose observance is not mandated there (see Esther 9:23–32); (6) celebrating Hanukkah, a holiday commemorating events that took place in the second century b.c., well after the Tanakh was already completed; and (7) reciting the Hallel prayer on certain occasions.
Although some Jewish leaders differed with Maimonides in including these rabbinic commandments in the count of 613, all traditional Jews recognize these seven commandments as divinely given through the authority of the rabbis. Thus, as noted earlier (#14), when a Jewish woman lights the Sabbath candles, she blesses God “who commanded us to kindle the Sabbath candles,” even though this is not written in the Torah but rather comes from the rabbis.
The Hebrew acronym for 613 is taryag, as the Hebrew letter t equals 400, r equals 200, y equals 10 and g equals 3. Thus the 613 commandments are known in Hebrew as taryag mitzvoth. In keeping with Rabbi Simlai’s statement, the commandments are divided into negative and positive precepts (that is, “Thou shalt not” and “Thou shalt”). Because of the destruction of the Temple and the lack of a functioning Temple priesthood, Jews today can observe, as written in the Torah, only 77 out of the 365 negative commandments and 194 out of 248 positive commandments. This is one of the major reasons that religious Jews pray three times daily for the rebuilding of the Temple and the redemption of their people: They are eager to perform the rest of the commandments!
I’ll close this answer with the entire lengthy passage from the Talmud that I mentioned earlier (b. Makkot 23b–24a). You’re in for a surprise!
R. Simlai when preaching said: Six hundred and thirteen precepts were communicated to Moses, three hundred and sixty-five negative precepts, corresponding to the number of solar days [in the year], and two hundred and forty-eight positive precepts, corresponding to the number of the members of man’s body. Said R. Hamnuna: What is the [authentic] text for this? It is, Moses commanded us torah, an inheritance of the congregation of Jacob, ‘torah’ being in letter-value, equal to six hundred and eleven, ‘I am’ and ‘Thou shalt have no [other Gods]’ [not being reckoned, because] we heard from the mouth of the Might [Divine]. David came and reduced them to eleven [principles], as it is written, A Psalm of David. Lord, who shall sojourn in Thy tabernacle? Who shall dwell in Thy holy mountain?—[i] He that walketh uprightly, and [ii] worketh righteousness, and [iii] speaketh truth in his heart; that [iv] hath no slander upon his tongue, [v] nor doeth evil to his fellow, [vi] nor taketh up a reproach against his neighbour, [vii] in whose eyes a vile person is despised, but [viii] he honoureth them that fear the Lord, [ix] He sweareth to his own hurt and changeth not, [x] He putteth not out his money on interest, [xi] nor taketh a bribe against the innocent. He that doeth these things shall never be moved. ‘He that walketh uprightly’: that was Abraham, as it is written, Walk before Me and be thou whole-hearted. ‘And worketh righteousness,’ such as Abba Hilkiahu. ‘Speaketh truth in his heart,’ such as R. Safra. ‘Hath no slander upon his tongue,’ that was our Father Jacob, as it is written, My father peradventure will feel me and I shall seem to him as a deceiver. ‘Nor doeth evil to his fellow,’ that is he who does not set up in opposition to his fellow craftsman. ‘Nor taketh up a reproach against his neighbour’; that is he who befriends his near ones [relatives]. ‘In whose eyes a vile person is despised’; that was Hezekiah the king [of Judah] who dragged his father’s bones on a rope truckle-bed. ‘He honoureth them that fear the Lord’; that was Jehoshaphat king of Judah, who every time he beheld a scholar-disciple rose from his throne, and embraced and kissed him, calling him Father, Father; Rabbi, Rabbi; Mari, Mari! ‘He sweareth to his own hurt and changeth not,’ like R. Johanan; for R. Johanan [once] said: I shall remain fasting until I reach home. ‘He putteth not out money on interest,’ not even interest from a heathen. ‘Nor taketh a bribe against the innocent,’ such as R. Ishmael son of R. Jose. It is written [in conclusion], He that doeth these things shall never be moved. Whenever R. Gamaliel came to this passage he used to weep, saying: [Only] one who practised all these shall not be moved; but anyone falling short in any of these [virtues] would be moved! Said his colleagues to him: Is it written, ‘He that doeth all these things [shall not fall]’? It reads, ‘He that doeth these things’, meaning even if only he practises one of these things [he shall not be moved]. For if you say otherwise, what of that other [similar] passage, Defile not ye yourselves in all these things? Are we to say that one who seeks contact with all these vices, he is become contaminated; but if only with one of those vices, he is not contaminated? [Surely,] it can only mean there, that if he seeks contact with any one of these vices he is become contaminated, and likewise here, if he practises even one of these virtues [he will not be moved].
Isaiah came and reduced them to six [principles], as it is written, [i] He that walketh righteously, and [ii] speaketh uprightly, [iii] He that despiseth the gain of oppressions, [iv] that shaketh his hand from holding of bribes, [v] that stoppeth his ear from hearing of blood, [vi] and shutteth his eyes from looking upon evil; he shall dwell on high. ‘He that walketh righteously,’ that was our Father Abraham, as it is written, For I have known him, to the end that he may command his children and his household after him, etc.; ‘and speaketh uprightly,’ that is one who does not put an affront on his fellow in public. ‘He that despiseth the gain of oppressions,’ as, for instance, R. Ishmael b. Elisha; ‘that shaketh his hand from holding of bribes,’ as, for instance, R. Ishmael son of Jose; ‘that stoppeth his ear from hearing of blood’, one who hears not aspersions made against a rabbinic student and remains silent, as once did R. Eleazar son of R. Simeon; ‘and shutteth his eyes from looking upon evil,’ as R. Hiyya b. Abba [taught]; for R. Hiyya b. Abba said: This refers to one who does not peer at women as they stand washing clothes [in the court-yard] and [concerning such a man] it is written, He shall dwell on high.
Micah came and reduced them to three [principles], as it is written, It hath been told thee, O man, what is good, and what the Lord doth require of thee: [i] only to do justly, and [ii] to love mercy and [iii] to walk humbly before thy God. ‘To do justly,’ that is, maintaining justice; and ‘to love mercy,’ that is, rendering every kind office; ‘and walking humbly before thy God,’ that is, walking in funeral and bridal processions. And do not these facts warrant an a fortiori conclusion that if in matters that are not generally performed in private the Torah enjoins ‘walking humbly,’ is it not ever so much more requisite in matters that usually call for modesty? Again came Isaiah and reduced them to two [principles], as it is said, Thus saith the Lord, [i] Keep ye justice and [ii] do righteousness [etc.]. Amos came and reduced them to one [principle], as it is said, For thus saith the Lord unto the house of Israel, Seek ye Me and live. To this R. Nahman b. Isaac demurred, saying: [Might it not be taken as,] Seek Me by observing the whole Torah and live?—But it is Habakuk who came and based them all on one [principle], as it is said, But the righteous shall live by his faith.
Yes, the concluding comment is that the 613 commandments were reduced to one, as expressed in Habakkuk 2:4, “The just shall live by his faith” (kjv)—a favorite text of Paul (see Romans 1:17; Galatians 3:11). Of course, this is not to say that the Talmudic rabbis were Christians, but it is to say that when Paul boiled everything down to the just living by faith, he was in good company.