Know thou that the 613 Precepts of the Law form a compact with the Holy One--blessed be He!--and with Israel, as it is often explained in the Zohar. It is written (Exod. iii. 15), "This is My name, and this is My memorial." "My name," in the Hebrew characters, together with "Yeho," amounts numerically to 365; "Vah," together with "My memorial," amounts to 248. Here we have the number 613 in the Holy One--blessed be He! The soul is a portion of God from above, and this is mystically intimated by the degrees of "breath, spirit, soul," the initial and final letters of which amount to 613, while the middle letters of these amount to the number of "Lord, Almighty, God." The soul of Moses our Rabbi--peace be on him!--embraced all the souls of Israel; as it is said, Moses was equivalent to all Israel. "Moses our Rabbi" amounts to 613; and "Lord God of Israel" also amounts to 613.
Now let us illustrate the subject of "fear and love." Fear proceedeth from love and love proceedeth from fear. And this you may demonstrate by writing their letters one over the other, and then dividing them by horizontal and perpendicular lines, thus Love perfecteth fear, and fear perfecteth love. This is to teach thee that both are united together.
The Holy One--blessed be He!--often brings affliction on the righteous though they have not sinned, in order that they may learn to keep aloof from the allurements of the world and eschew temptation to sin. From this it is plain that afflictions are good for man, and therefore our Rabbis, of blessed memory, have said, "As men bless with joy and a sincere heart for a benefit received, so likewise ought they joyfully to bless God when He afflicts them, as, though the special blessing be hidden from the children of men, such affliction is surely intended for good.... Or most souls being at present in a state of transmigration, God requites a man now for what his soul merited in a bypast time in another body, by having broken some of the 613 precepts."
Thus we have the rule: No one is perfect unless he has thoroughly observed all the 613 precepts. If this be so, who is he and where is he that has observed all the 613 precepts? For even the lord of the prophets, Moses our Rabbi--peace be on him!--had not observed them all; for there are four obstacles which hinder one from observing all: (1.) There is the case of complete prevention, such as the law of the priesthood, the precepts of which only priests can observe, and yet these precepts are included in the 613. Besides, there are among the number precepts appertaining to the Levites which concern neither priests nor Israelites, and also others which are binding on Israelites with which priests and Levites have nothing whatever to do. (2.) Then there are impossible cases, as, for instance, when one cannot observe the precept which enforces circumcision, because he has not a son to circumcise. (3 and 4.) There are also conditional and exceptional cases, as in the case of precepts having reference to the Temple and to the land of Israel.