Midrasch zu Ijow 20:21

R. Elazar said again: "A house in which the words of the Torah are not heard during the night will finally be burned, as it is said (Job 20, 26) Entire darkness is laid by for his treasures: a fire not blown by man will consume him; it will destroy anyone (Sarid) left in his tent. Sarid refers to a scholar, as it is said (Joel 3, 4) Among the remnant (shridim) whom the Lord calleth." R. Elazar said again: "He who does not benefit scholars with his estate will never come into any manner of blessing, as it is said (Job 20, 21) Nothing was spared (Sarid) from his craving to eat; therefore shall his wealth not prosper. And the word Sarid refers to a school, as it is said (Joel 3) Among the remnant (Shridim) whom the Lord calleth." And from the same passage, R. Elazar said again: "He who does not leave any bread after his meal will not reap the fruits of any blessing, as it is said (Job 20) Nothing was spared (Sarid) from his craving, and Sarid refers to a scholar as above. But did not R. Elazar say elsewhere that he who left pieces of bread after his meal is considered as if he were worshipping idols, as it is said (Is. 65, 11) That set out a table for the god of fortune and that fill for destiny the drink-offering. This presents no difficulty. In the latter saying he means, that he puts a whole loaf on the table [which is prohibited], but in the former passage he speaks of leaving some crumbs of bread for the poor. R. Elazar said again: "He who changes his word is considered as if he were to worship idols; it is written here (Gen. 27, 12) I will seem to him as a deceiver; and it is written (Jer. 10, 15) They are vanity, the work of deception." R. Elazar said again: "A man shall always remain obscure (without an office) and he will live." R. Zera said: "We have also taught so in the following Mishna: If there seems to be leprsoy in a house which is dark, windows must not be opened for investigation." Hence it is inferred as above.