Musar su Proverbi 10:1

And the verse in Proverbs 24:30-31 — "I went by the field of the slothful, and the vineyard of the man void of understanding; and lo, it was all grown with thistles, the face thereof was covered with nettles, and the stone thereof was broken down" — was expounded by our Sages as follows (Aboth de-Rabbi Nathan, chap. 24) : He who does not constantly review his Talmud will at first forget the chapter headings, then he will change the words of the Sages, and finally he will say of unclean that is clean and of clean that is unclean, and thus he destroys the world. We thus see that he who does not constantly review his studies cannot declare the Law properly, but errs because he cannot decide between the many teachings. And it is said (Midrash Prov. 10:1) : Rabbi Ishmael said, "Come and see, how severe is the Day of Judgment ! For the Holy One, Blessed be He, will in the future judge all the world in the Valley of Jehosephat; and when a scholar comes before him, He will say to him, 'Did you occupy yourself with Torah?' Then he will say to Him, 'Yes.' Then the Holy One, Blessed be He, will say to him, 'Since you have admitted this before Me, tell Me what you have read, what you have studied, and what you have heard in the academy?' It is on this basis that our Sages said, 'Everything that a man has read should be at his fingertips, so that shame and humiliation will not overtake him on the Day of Judgment.' "

In connection with the debate in the Talmud (Shabbat 55a) whether זכות אבות, reliance on the merits of our patriarchs is still effective today, and if not, when it ceased to be so, the author makes the following observations: Tosafot quote a verse proving that even nowadays, i.e. after the destruction of the second Temple, this merit has not expired, and that we mention it in our prayers in order to remind G–d of it. I believe (author) that there is a difference between someone saying: "Please remember so and so," and someone saying: "Please do not forget so and so." The opinions in the Talmud which try and determine the merit of the forefathers ceased to be effective refer to G–d no longer actively remembering the merit of the patriarchs but simply not having forgotten them. The author of our prayer therefore refers to the merits of our forefathers כלא היו, "as if they had never existed," as distinct from "never having existed, having been used up." This is the difference between אין, and כאין. The חכמים mentioned in our prayer are the twelve sons of Jacob, all of whom accumulated powerful merits, so much so that Solomon describes them as a source of joy to their father (Proverbs 10,1). We also have a verse in Proverbs 24,3: בחכמה יבנה בית, "a house is built by wisdom," which is a reference to the house of Jacob. There used to be a period when the merits of the forefathers were constantly on G–d's mind. This was when the High Priest wore the breastplate. During those years the knowledge of what G–d desired flowed to us through the אורים ותומים, the oracle contained in that breastplate. Nowadays, alas, we are as if bereft of knowledge, i.e. כבלי מדע.