The Mishnah taught: A Jewish woman should not act as a wet nurse for the baby of a female idolater. The reason is because she is giving life to a young idolater.

(R. Yosa): According to this, it is prohibited to teach them a trade (because as a result, they will have a livelihood).

It is like the case of two families of craftsman in Giro, one made glass and one made women's scarfs. The glass makers did not teach their trade to the idolaters and they retained their money and the scarf-makers taught their trade to the idolaters and they lost their money.

The Mishnah taught: But a female idolater may act as a wet nurse for a Jewish woman. As the pasuk states (Yishayah 49:23), "And kings will be your nurturers and their princesses your wet nurses".

Beraisa: The baby can nurse from an idolater and from a non-Kasher animal (if there is no alternative) and their milk maybe be brought to him, and there is no concern for a prohibition against an idolater's milk or a non-Kasher animal's milk.