Kelal (Hebrew, surround, include) is a summary of rabbinic Judaism of the essential meaning of Torah, or a series of halakhoth in the Mishnah. One of the ideals in teaching is to follow derek qezarah, the (shortest) way. Rabbis, therefore, would search for a statement, preferably a verse from the Torah, which would summarize the purpose and meaning of the covenant. Perhaps the most famous kelal was of Hillel, “What ever you would not have people do to you, do not do to them.” Aqiba said Leviticus 19:18, “You shall not avenge, nor bear any grudge against any of thy people, but you shall love thy neighbor; I am the Lord,” “the great kelal in the Torah.” They are many more examples. A.G.H.
Bowker, John, The Oxford Dictionary of World Religions, New York, Oxford University Press, 1997, pp. 540-541