כְּבֹ֣ד אֱ֭לֹהִים הַסְתֵּ֣ר דָּבָ֑ר וּכְבֹ֥ד מְ֝לָכִ֗ים חֲקֹ֣ר דָּבָֽר׃
Слава Богу, чтобы скрыть вещь; но слава королей состоит в том, чтобы искать дело.
Mishneh Torah, Tefillin, Mezuzah and the Torah Scroll
It is a rule dating back to Moses who received it on Sinai that the scroll of the Law should be written on Gewil (whole hide parchment), and the writing should be on the side which had been next to the hair. The Tephillin should be written on Kelaf (the exterior part of the split hide) and the writing should be on the side which had been nearer the flesh; and the Mezuzah should be written on Duxustus (made of the inner part of the split hide), on the side which had been nearer the hair. If, on a Kelaf, one writes on the side that had been next to the hair, or, on a Gewil or Duxustus, one writes on the side that had been next to the flesh, the Scroll, Tephillin or Mezuzah so written is unfit for use.
Sefer Chasidim
When Rabbi Simeon ben Gamaliel and Rabbi Ishmael went forth to be killed, said Rabbi Simeon b. Gamaliel to Rabbi Ishmael “I do not know why I am going forth to be killed.” He said, “Perhaps when you were expounding in public, your heart rejoiced and your heart was gratified.” He said, “You have consoled me.”1Aboth of Rabbi Nathan, ed. Solomon Schechter (reprint of Vienna Edition of 1887; New York: P. Feldheim Publisher, 1945), version A, Chapter XXXVIII, p. 114.
/2/ Yalkut Shimoni (New York—Berlin: Horeb Publishers, 1926), Kings, par. 244, p. 768. And so should every man do, he should repent of his evil doings without ostentation and let him go and perform his tasks and matters privately, let his heart not profit at all from his good works; also all matters relative to piety let him do in concealment. For it is already stated, “conceal thy things” (Prov. 25:2) “and walk humbly with thy God” (Mic. 6:8). And let a man not claim credit for himself that his intentions are heavenly. Let him beware lest his heart profit or rejoice. For if his heart rejoices before the world, he has indeed already received a part of the reward for that command in this world. If his heart rejoiced against his will, that is to say without his knowledge or intent, let him condition his heart to overcome his passion and let him desist from that act in which his heart rejoiced. For many of those now deceased performed this specific deed and performed meritorious acts without number; they have passed on to their eternal rest and the matter is forgotten, they have left no remembrance because their memory is forgotten in this world with none to recall them, but their memory is for the after-life. Therefore what advantage or profit is mine if they praise me in this world? So should he think at all times also at night when retiring. He must be concerned lest eternal sleep overtake him and he will awaken no more. Wherefore should he continue to rejoice that they praise him in this world? All is vanity and a striving after wind.
/2/ Yalkut Shimoni (New York—Berlin: Horeb Publishers, 1926), Kings, par. 244, p. 768. And so should every man do, he should repent of his evil doings without ostentation and let him go and perform his tasks and matters privately, let his heart not profit at all from his good works; also all matters relative to piety let him do in concealment. For it is already stated, “conceal thy things” (Prov. 25:2) “and walk humbly with thy God” (Mic. 6:8). And let a man not claim credit for himself that his intentions are heavenly. Let him beware lest his heart profit or rejoice. For if his heart rejoices before the world, he has indeed already received a part of the reward for that command in this world. If his heart rejoiced against his will, that is to say without his knowledge or intent, let him condition his heart to overcome his passion and let him desist from that act in which his heart rejoiced. For many of those now deceased performed this specific deed and performed meritorious acts without number; they have passed on to their eternal rest and the matter is forgotten, they have left no remembrance because their memory is forgotten in this world with none to recall them, but their memory is for the after-life. Therefore what advantage or profit is mine if they praise me in this world? So should he think at all times also at night when retiring. He must be concerned lest eternal sleep overtake him and he will awaken no more. Wherefore should he continue to rejoice that they praise him in this world? All is vanity and a striving after wind.