Add one — or the number of letters, or the number of words — so that a count lands on its target. ברית ('covenant') sums to 612, and with the word itself counted it is 613, the number of the commandments. תורה is 611, and the tradition adds the two commandments spoken directly at Sinai to reach the same 613.
Kolel is the rule that the thing counted is itself part of the count: the word, its letters, its verse. It turns gematria from arithmetic into exegesis, and it is also the honest reason the practice can find almost anything, because a near miss is closed by adding one. Every school of the tradition uses it, and almost none of them says so in the sentence where it matters.
Nothing in the library points at this entry yet.