God made Jeremiah a prophet by putting his words into his mouth. That was in line with the Old Testament’s word for a prophet, that was nabi. (That was a child’s name for his or her mouth.)
When we are baptized we are baptized into a close union with Christ. That union gives each of us a share in his prophetic role. In our baptism, after the priest has poured on the water, he anoints our lips with chrism, consecrating them as prophets.
As prophets, we are set aside for the task of speaking God’s word to mankind. His word comes to us in the form of ideas that pop into our heads. Verses 10 and 11 of Isaiah 55 tell us how:
“Just as from the heavens the rain and snow come down, and do not return there until they have watered the earth, making it fertile and fruitful; giving seed to him that sows and bread to him who eats, so shall my word be that goes forth from my mouth.”
Our Gospel speaks of how receptive of God’s word, or how unreceptive of it we are. Our hearts can be like hardened paths where the word can’t sink it; or they can have layers of rock where the word can’t put down roots; are they can be given over to vices that choke out the word; or they are they can be like good ground where as God’s prophets we send out the word.