What is it that we mean when we talk about "labor"?
When we speak about childbirth, its meaning is very clear.
Its more common use, however, is connected to work.
We might define "labor" by the amount of effort one puts in, or more precisely, by the amount of sweat that is produced.
Or, labor might be something we measure economically: by how much one is paid, and in what form that payment is given.
Both approaches are valid and true: The first applies even to horses; the second is exclusively a human idea.
There is still another way to think about labor, related to neither effort nor pay, but rather, to the result or outcome that is produced.
This sense of labor–as a creative process–is what the Bible means when it says that God "worked" for six days in creating the world.
This labor is not tied to tiredness or to reward.
It is activity that causes something new to appear.
This perspective can also be applied to the way that we live and understand our lives as productive beings.
We should measure the result of a day of work by the criterion by which God evaluated His work: by what has been accomplished.
–Rabbi Adin Steinsaltz
From an essay, "Rest for the Weary Laborer" by Rabbi Adin Steinsaltz