DEUT400 One should not think that his livelihood depends on a particular source and that, if that source were to fail, there would be no other way for him to earn a living. Rather he should rely on God for his sustenance and realize that to the Creator all the means are equal--He will support him by whatever means and at any time and from whatever elements He wishes, as Scripture says: “For nothing can prevent God from saving, whether by many or by few” (Shemuel I, 14:6); “It is Hashem your God who gives you the power to become prosperous” (Devarim 8:18); “‘Not by might and not by power, but by My spirit,’ said God of Hosts” (Zecharyah 4:6).