Please notice that it is workers the Lord sends, field hands, day laborers. It is unglamorous, sweaty, grubby, work that He sends His workers into. The kind that gets dirt under your fingernails. It goes on in the day to day grind of life, around the dinner table, in casual conversation with your neighbor and co-worker, beside the sick bed, on the road. It goes on in the Christian congregation, where Christ's Word is preached and taught, where Christ's Body and Blood are eaten and drunk, where God's people are baptized and taught.
Field work appears ordinary and everyday, even boring at times.
But this is Jesus' compassion at work in the nooks and crannies of life, hidden under the ordinary. That's where His harvest field is. So great and deep is Jesus compassion for you, that He sends you preachers to preach with His authority and commission. Jesus called His Twelve to Himself, and He authorized them to preach and to heal, to do the same works that He Himself was doing. He sent them into His harvest as His ministers, his authorized agents who spoke and acted in His name.