Relying on a miracle for Parnossa is prohibited

 Igros Moshe (OH 2:111): We see clearly from the gemora that it is prohibited to depend on a miracle to provide livelihood without us doing any action or having an occupation. Even though it is necessary to know that all the profit which comes from working or business is only from G d according to what was fixed on Rosh HaShanna - but this is only when we have some occupation or business dealings. This necessity for effort is stated in the Torah “by the sweat of your brow you will eat bread” and is discussed at the end of Kiddushin. Even according R’ Nehorai who only taught his son Torah and not a trade - indicating that there is no need to teach a trade to one’s son - agrees that one cannot rely on a miracle. His view is that the majority of people cannot learn Torah and a trade at the same time while young. Thus his position is that when a person is an adult, G d will provide him some way of earning a living and supporting his family - even if he didn’t learn a trade while a child. However as an adult even R’ Nehorai would agree that it is prohibited to do nothing and rely on a miracle. This understanding is seen in the Rambam who rules like R’ Nehorai that there is no need to teach a trade and rules in Hilchos Talmud Torah (3:10) that it is necessary to have an occupation….