The laborers are few

Last night, at a parish meeting, we looked at the passage from Luke where Jesus says, "The harvest is plentiful, but the laborers are few;" and I realized for the first time that the next part is not "Therefore, you should work much, much harder." Instead, Jesus says, "therefore ask the Lord of the harvest to send out laborers into his harvest."

I've always heard this passage interpreted with the "harvest" being souls in need of saving. But that doesn't make sense to me, looking at the full statement. It sounds to me like the harvest is some other good thing, and that the more people to make that harvest happen, the better. I'm not sure saving anyone has anything to do with it--not the other laborers, not the harvest. It was just interesting to me. I'll have to ponder this.