"Unless the Lord builds the house, its builders labor in vain. Unless the Lord watches over the city, the watchmen stand guard in vain. In vain you rise early and stay up late, toiling for food to eat - for He grants sleep to those He loves"
God is telling us there is a way of working without striving. There is a way to conduct business without sweating and toiling for outcome. His warning to each of us is to avoid thinking that outcome is based on our sweat and toil. Outcome is based on obedience. That outcome is sometimes more than we deserve. Sometimes it is less than we hoped for. His desire for each of us is to see Him working in our daily work life. He wants us to avoid looking to our own effort to gain an outcome.