The Talmud bolsters the above explanation based on a different baraita.

The Gemara notes that the obligations of a father toward his son are also taught in a different baraita: We learned this halakha, as the Sages taught in a baraita: A father is obligated with regard to his son to circumcise him; and to redeem him, a firstborn son, with payment of five shekels to a priest; and to teach him Torah; and to marry him to a woman; and to teach him a trade. And some say: A father is also obligated to teach his son to swim. Rabbi Yehuda says: Any father who does not teach his son a trade teaches him banditry, to be a robber and a crook.