Siman 558

(115.) I heard from his holy mouth regarding marian [nocturnal emissions], G-d save us — that he said the klippos [husks] of the man's seminal emissions go to them. And from this come their marian, G-d save us. We once heard from his holy conversations that he said from his holy mouth: "The greatest service that is great among great things in the service of G-d is easier to do than a business transaction that one troubles oneself for livelihood and worldly matters." For we see how much exertion people put in for livelihood and worldly occupations... ...For we see how much exertion a person exerts in order to travel to some fair and market day — that immediately at the conclusion of the Sabbath he must toil and search for a wagon, and he hurries very much to load his merchandise onto the wagon with great exertion. And afterwards he must travel all night and wander — sleep departs from his eyes and his whole body is broken from having to sit on a loaded wagon — and other toils and exertions like these, as is known to the world. And afterwards he must stand on his feet all day etc. — and particularly in the intense cold days etc. And all these heavy and hard toils and exertions he troubles himself with on a doubt — for perhaps he will profit some small sum, or perhaps he will even lose the expenses, as is common most of the time. Behold: for the matters of livelihood of this world one troubles oneself so with such exertions on the doubt of a small sum. And the greatest service that is great among great things is prayer. And even so, when one stands to pray, one prays and completes the prayer. (Brought in Likutay Halachos, Laws of the Evening Prayer, Law 4, marking 7.)