pasture: the grazing ground where a flock is fed and kept
At its root this word names whatever is dealt out or apportioned, and its oldest, most concrete use is the grazing a shepherd portions out to his sheep. A pasture is not just any field but the place a flock is led to feed, the provision that keeps it alive.
In the only New Testament verse that uses the word this way, Jesus promises that whoever enters through him will go in and out and find pasture. The picture carries the full weight of the Old Testament shepherd promises, especially Ezekiel 34, where God himself vows to feed his scattered flock in good, rich grazing land. To find pasture is to find life, safety, and everything the sheep needs from a faithful shepherd.
So the word here is more than a farming term. It stands for the spiritual nourishment and secure life that come through Jesus, pictured as the good shepherd leading his own to where they are fed and kept.