G-d, your G-d, will bless you in all that you do.
G-d will bless you in all that you do: The sages understand this verse to imply that although G-d determines which of us will succeed in our efforts to provide ourselves with a livelihood and amass wealth, we must not rely solely on His providence, but must rather put forth reasonable efforts to earn our living naturally.
By the same token, however, we must keep in mind that our efforts are not the direct cause of our material success; they are only a “vessel,” a receptacle to contain G-d’s blessing. In this context, along with taking care to ensure that our “vessels” are fit to receive G-d’s blessing, our main concern should not be with the vessels per se but with making ourselves worthy of receiving the blessing with which we hope G-d will fill our vessels.
On one level, this orientation is based on our recognition that G-d is the master of nature, and therefore, if we want our natural efforts to be successful, we should ensure that they accord with His will.
On a deeper level:
Our livelihood is an altogether miraculous affair, and the natural efforts we are required to engage in are no more than a ruse that G-d arranged so that it would appear as if we are earning our livelihood through totally natural means.
In this context, unduly devoting ourselves to enhancing the efficacy of our jobs while neglecting to enhance our spiritual worthiness of G-d’s blessing is like working feverishly to sew sturdy pockets into our garments while forgetting to go to work to earn the money with which to fill them.
—From the Kehot Chumash