Ruach Chaim (5:05) One of the ten miracles that occurred in the Temple was that the rain did not put out the fire burning on the wood for the sacrifices... The claim of most people is that in our times it is not possible to be fully engaged in Torah study because of the concern and effort to earn a living. To this he is responding that this is absolutely wrong! Rather a person needs to have bitachon in G-d that he will be able to engage fully in Torah study. This that it says that the rains will not extinguish the fire is a a metaphor for parnossa, In other words there will be no loss by fully engaging in Torah study which is comparable to fire.
Ruach Chaim (Avos 1:14) He used to say If I am not for myself who will be for me? You should know that the yetzer harah blinds the eyes of a person by saying constantly to him “How can you be involved in Torah study since it is required to earn a living for the sake of your wife and children especially at the present time when the burden of earning a living is extremely heavy, While that in truth is the blinding advice of the evil inclination. In reality our Sages tell us that before the baby is formed it has already been decreed whether he will be rich or poor and this is typically for his entire life. Furthermore on each individual year it is decreed from Rosh Hashanna what wealth he will receive. Therefore all his efforts will not get for him more than has been decreed and in fact he will get his portion with minimal effort. In contrast his accomplishment in Torah is proportional to his effort. Thus the Mishna is saying regarding Torah If I am not for myself who will be for me? That is because It all depends on me. In contrast the Mishna continues that regarding this world if I rely totally on myself than what am I
Rambam (Hilchos Shemitta 13:12–13): Why didn’t the tribe of Levi merit an inheritance in the land of Israel as well as the spoils of war like the other tribes? It is because they were given the responsibility to serve G d and to teach His righteous ways to the masses… Therefore they were separated from the ways of world and were not involved in war like the rest of Israel and they neither inherited nor obtained things by means of physical endeavors. They were G d’s army and G d provided for them. However, this way of life is not exclusively for the tribe of Levi but in fact any person in the world whose spirit moves him. He understands by himself to separate and stand before G d to serve Him in order to know G d. If he goes in the upright path, as G d desired then the yoke of constant worry characteristic of mankind will be taken from him. He will be sanctified, as holy of holies and G d will be his portion and inheritance forever. He will consequently obtain in this world that which he needs in the same way as the Cohanim and Leviim…