About the 613 biblical commands and Azharot that lists them
The Azharot, meaning “exhortations,” are poetical listings of the 613 commandments that Jewish tradition states are contained in the Five Books of Moses. The very first such poetical listing was made by the Babylonian Jewish leader Saadiah Gaon (882-942) and another famous one was done by the eleventh century Spanish poet Solomon ibn Gabirol. Many Sephardic Jewish congregations read ibn Gabirol’s version during the holiday of Shavuot, Pentecost, because the holiday of Shavuot is seen today as remembering the revelation of the Torah to Moses.
The first report that the Torah contains 613 commandments occurred in the third century CE, when Rabbi Simlai mentioned it in a sermon that is recorded in the Babylonian Talmud, Makkot 23b. It appears that he invented the number 613 because it fit his sermon: A person should observe the Torah with all his body parts (248) every day (365). The two numbers equaling 613. The Talmud states: “Rabbi Simlai gave as a sermon [darash Rabi Simlai]: 613 commandments were communicated to Moses, 365 negative commands, corresponding to the number of solar days [in a year], and 248 positive commands, corresponding to the number of the members [bones covered with flesh]of a man’s body.”
As far as we know, no one had a concept that there were 613 biblical commandments before Rabbi Simlai offered his sermon. In fact, 150 years before Rabbi Simlai, the second century Simeon ben Azzai is quoted as saying there are 300 biblical commands. E. E. Urbach (1912-1991) wrote: “in the Tannaitic sources [until the third century] this number  is unknown.”
Ibn Ezra (1089–1167) recognized that if one counts all of the divine commandments recorded in the Bible, the number would be well over a thousand; and that if only the commandments relevant to his day were numbered, the total would be less than three hundred. He wrote in his Yesod Moreh 2, “Some sages enumerate 613 mitzvot [divine commandments] in diverse ways…but the truth is that there is no end of the number of mitzvot…and if we were to count only the root principles…the number of mitzvot would not reach 613.”
Nachmanides (1194–1270) writes in his Hasagot, his critical commentary to Maimonides’ Sefer Hamitzvot, that the 613 count is a matter of dispute and there is no certainty that it is true, but since “this total has proliferated throughout the aggadic literature…we ought to say that it is a tradition from Moses at Sinai.”
Judah ibn Balaam (eleventh century) rejected the notion that there are 613 biblical commands. He wrote “To my mind, the dictum [of Rabbi Simlai] was said only as an approximation.”
Gersonides (1288–1344) also rejected the idea that there are 613 biblical commandments. He wrote that the number is only homiletical, teaching that Jews should obey God’s laws with their entire being [248 organs] every day (about 365 days in the solar calendar).
Rabbi Shimon ben Tzemach Duran (1361–1444) summed up the above-mentioned views: “Perhaps the agreement that the number 613…is just Rabbi Simlai’s opinion, following his own explication [account] of the mitzvot. And we need not rely on his explication when we come to determine the law, but rather on the Talmudic discussion.”
In view of the facts mentioned above, it should come as no surprise that the enumeration of 613 biblical commandments was first mentioned to dramatize a sermon and the early attempts to list the 613 commandments failed because there are not 613 biblical commands. In his introduction to his own listing, in Sefer Hamitzvot, Maimonides (1138–1204) pointed out some attempts to list the 613 in Azharot, included mistaken errors such as inserting post-biblical rabbinical commandments as the lighting of Chanukah candles in the list of biblical commandments.
Maimonides’ itemization of the 613 biblical commandments is the most logical, but it is not accepted by all rabbis. Nachmanides, for example, rejected some of his items and included others.
Thus Azharot may be good poetry, but poor theology.