"and places the thongs of labor and preoccupation upon his arms" he's saying that the worldly needs are what bind him-the world bonds and confines him because money is a part of the material affairs of the world and a person who enters the desire for money, stops functioning like a human being as it is written "The lover of silver will not be satiated with silver." a person who does not train himself- and turns into someone who loves money every person needs money, but there's a difference between needing money and loving money needing means that he needs to live- so he works in order to receive his income and this is what he uses in order to live. 