R’ Yehudah says: A bachelor may not herd cattle, and two bachelors may not sleep in one garment; the Sages, however, permit [it].  Anyone whose business is with women may not be alone with women. A man should not teach his son a trade [which involves being] among women.  R’ Meir says: A man should always teach his son a clean and light trade, and he should pray to the One to Whom wealth and possessions belong, because there is no trade which does not include poverty and wealth, since poverty is not from the trade, nor is wealth from the trade; rather, all is in accordance with one’s merit.  R’ Shimon ben Elazar says: Have you ever seen a wild animal or a bird which has a trade? Yet they are sustained without difficulty. But they were created only to serve me, and I was created to serve my Master. Does it not follow that I should be sustained without difficulty? However, I have corrupted my deeds and curtailed my sustenance.  Abba Guryan of Tzadyan, quoting Abba Gurya, says: A man should not teach his son [to be] a donkey driver, a camel driver, a sailor, a shepherd, or a storekeeper, because their trade is the trade of robbers. R’ Yehudah, quoting him, says: Most donkey drivers are evildoers; and most camel drivers are righteous men; most sailors are pious men; the best of doctors to Gehinnom; and the most righteous of animal-slaughterers is a partner with Amalek.  R’ Nehorai says: I abandon every trade in the world and I teach my son only Torah, for a man benefits from its rewards in this world, and the principal remains for the World to Come. All other trades are not so; when a man becomes sick, old, or afflicted, and he cannot engage in his work, he dies of starvation. But Torah is not so; rather, it guards him from all evil in his youth, and it provides him with benefit and hope in his old age. Regarding his youth, what does it say? And those whose hope is in HASHEM shall renew their strength (Isaiah 40:31). Regarding his old age, what does it say? They will still be fruitful in old age (Psalms 92:15). And likewise it says regarding our forefather Abraham —- peace upon him (Gen. 24:1): And Abraham was old ... and HASHEM blessed Abraham with everything. We find that our forefather Abraham fulfilled the entire Torah before it was given, as it says (ibid. 26:5): Because Abraham obeyed My voice and safeguarded My Ordinances, My Commandments, My Decrees, and My Teachings.