At thirteen years of age, a boy becomes bound to observe the (613) precepts of the law. _Avoth_, chap. 5. Rabbi Ishmael says the law is to be expounded according to thirteen logical rules. _Chullin_, fol. 63, col. 1. The thirteen rules of Rabbi Ishmael above referred to are not to be found together in any part of the Talmud, but they are collected for repetition in the Liturgy, and are as follows:-- 1. Inference is valid from minor to major. 2. From similar phraseology. 3. From the gist or main point of one text to that of other passages. 4. Of general and particular. 5. Of particular and general. 6. From a general, or a particular and a general, the ruling both of the former and the latter is to be according to the middle term, i.e., the one which is particularized. 7. From a general text that requires a particular instance, and _vice versà_. 8. When a particular rule is laid down for something which has already been included in a general law, the rule is to apply to all. 9. When a general rule has an exception, the exception mitigates and does not aggravate the rule. 10. When a general rule has an exception not according therewith, the exception both mitigates and aggravates. 11. When an exception to a general rule is made to substantiate extraneous matter, that matter cannot be classed under the said general rule, unless the Scripture expressly says so. 12. The ruling is to be according to the context, or to the general drift of the argument. 13. When two texts are contradictory, a third is to be sought that reconciles them. Rabbi Akiva was forty years of age when he began to study, and after thirteen years of study he began publicly to teach. _Avoth d'Rab. Nathan._ Thirteen treasurers and seven directors were appointed to serve in the Temple. (More there might be, never less.) _Tamid_, fol. 27, col. 1. Thirteen points of law regulate the decisions that require to be made relative to the carcass of a clean bird. _Taharoth_, chap. i, mish. 1. A man must partake of fourteen meals in the booth during the Feast of Tabernacles. _Succah_, fol. 27, col. 1. Traditional chronology records that the Israelites killed the Paschal lamb on the fourteenth day of Nisan, the month on which they came out of Egypt. They came out on the fifteenth; that day was a Friday. _Shabbath_, fol. 88, col. 1.