With rules like these, couldn't you make the Torah say anything?
Fair question. The rules come with limits. The first shows up in the first example in the Sifra (the early commentary on Vayikra that this list opens).
Miriam spoke against Moshe and was struck with a skin disease. God says to Moshe: if her father had spat in her face, would she not hide in shame for seven days? The Sifra reasons: if a father's anger means seven days, God's should mean fourteen. Then it stops: "It is enough for what is derived to be like what it was derived from." The source said seven, so Miriam stays outside the camp for seven. A kal vachomer can carry a law to a new case. It cannot make the law bigger. The Gemara calls this limit part of the Torah's own law.
Rule two has a tighter limit. A gezerah shavah links two laws because the same word appears in both. The Gemara rules: a person may build a kal vachomer on his own, but not a gezerah shavah. Rashi (the classic commentator, France, 1000s) explains why: maybe that word is there to teach something else. So a gezerah shavah has to be received from one's teachers, going back to Sinai.
And a kal vachomer that anyone may build, anyone may knock down. In the Hillel story in the Story section, the Gemara says his kal vachomer was answered: the daily offering is brought far more often, so maybe that is why it overrides Shabbat. His other proof, the one he had from his teachers, is the one that stood.
A law the highest court reached with these rules is not locked forever. The Rambam (Maimonides, who died in 1204) rules that if a later high court sees a reason to read it differently, it may overturn the earlier ruling. Laws received from Moshe are different. About those, he says, there is never an argument (more on that at the first Eizehu Mekoman passage).
So the rules did not let one clever person get the answer he wanted. An argument made with them could be checked, limited, and sometimes beaten.
Sifra, Baraita of Rabbi Yishmael,Bamidbar 12:14,Bava Kamma 25a,Pesachim 66a, with Rashi,Niddah 19b,Rambam, Laws of Rebels 1:3 and 2:1The Torah contradicts itself? And the siddur says so out loud?
Read rule thirteen again: "two verses that contradict each other, until a third verse comes and decides between them." The rule does not hide the problem. It names it, and it tells you what to do next: look for a third verse.
The Sifra gives a case. One verse says that when Moshe came into the Tent of Meeting to speak with God, he heard the voice. Another says Moshe could not come into the Tent of Meeting. Which is it? The answer is in the rest of that second verse: "because the cloud rested on it." While the cloud was there, Moshe did not go in. When it lifted, he went in and spoke with God.
A second case is about Mount Sinai. One verse says God came down onto the mountain. Another says He spoke to Israel from heaven. The Sifra's answer: God bent the heavens down onto the mountain and spoke from there. The Mekhilta (the matching early commentary on Shemot) records an argument about it. That answer is Rabbi Akiva's. Rabbi Yishmael points to a verse in Devarim: "From heaven He let you hear His voice, to discipline you, and on earth He showed you His great fire."
Abudarham (a commentary on the prayers, Spain, about 1340) adds a case from the first page of the Torah. "In the beginning God created the heavens and the earth" sounds as if the heavens came first. A chapter later it says "on the day Hashem God made earth and heavens." His third verse is from Yeshayahu: "My hand founded the earth and My right hand spread out the heavens. I call to them and they stand together."
In each of these cases neither verse is thrown out. More of the Torah's own words, a third verse or the rest of the same one, show how both can be true. That is what the rule sends a reader to look for. And the rabbis did not bury the question. They made it rule thirteen.
Sifra, Baraita of Rabbi Yishmael,Bamidbar 7:89; Shemot 40:35,Shemot 19:20 and 20:19; Devarim 4:36,Mekhilta DeRabbi Yishmael, Bachodesh 9,Abudarham, Baraita of Rabbi Yishmael,Bereishit 1:1 and 2:4; Yeshayahu 48:13Did Rabbi Yishmael just make these rules up?
It can look that way. The Torah never lists them, and the siddur opens with "Rabbi Yishmael says." But the sources show these rules in use well before him.
The Sifra itself, among its examples for the last rule, records another list in the name of an earlier sage: "Hillel the Elder taught seven rules before the elders of Beteira." Hillel lived generations before Rabbi Yishmael. His seven include rule one and rule two from this list, general-and-specific, and learning a thing from its context.
Rabbi Yishmael also had a teacher. The Gemara says he studied under Rabbi Nechunya ben HaKanah (the Ana BeKoach prayer says more about him), "who explained the whole Torah by general and specific," and so he did the same. Rules four through seven on this list are all built on general and specific.
Not everyone read the Torah his way. The same passage says Rabbi Akiva, who argues with him there, got a different method from his own teacher, Nachum Ish Gamzu: "including and excluding." The Gemara there shows the two methods giving two different laws from one verse.
They disagreed about something more basic too. When the Torah doubles a word, Rabbi Akiva learns something from the extra word. Rabbi Yishmael answers him: "The Torah spoke in the language of people." People repeat words when they talk, and so does the Torah.
So the sources do not describe an inventor. They describe a student who received a way of reading, and whose name is on the list of thirteen. Whether the wording of the list is his own or older still, the sources we opened do not say.
Sifra, Baraita of Rabbi Yishmael,Shevuot 26a,Sanhedrin 64b