John Gill's Exposition of the Whole Bible
Jeremiah 15:16
Thy words were found, and I did eat them, e.] The messages he was called to deliver unto others appeared to him to be of God, and they were as welcome to him as food is to a hungry man he cheerfully received them, treasured them up in his memory, digested them in his mind, and carefully retained them. So the doctrines of the Gospel, which are the words of God, and not of men, when by searching and close application they are found in the Scriptures, and under the ministry of the word, they are food to souls, sweet, savoury, wholesome, nourishing, and strengthening; not as merely heard externally, or only assented unto, or superficially tasted of; but when eaten, as Ezekiel's roll was by him; and which is done by faith, which receives, feeds upon, and digests the word; for, unless it is mixed with faith, it is not profitable:
and thy word was unto me the joy and rejoicing of mine heart; the messages which the prophet was sent with, even those which denounced grievous things against his people in case of impenitence, were gladly received by him, and he readily delivered them, hoping that they would be a means of bringing them to a sense of their sins, and to repentance for them, and so of preserving them from ruin; and especially those words or doctrines he had in commission to deliver, which respected the Messiah, his person, offices, kingdom, righteousness, and grace; the calling of the Gentiles, and the enlargement of the interest of Christ; the glory of his name, and the prosperity of his people in the latter day. The word of the Gospel, when received and eaten by faith, whether by ministers or people, is productive of spiritual joy and pleasure; the promises of it being exceeding precious; and the doctrines of it doctrines of grace, salvation, peace, pardon, and righteousness, by Christ, who is the sum and substance of them:
for I am called by thy name, O Lord God of hosts; what added to his joy was, that the name of the Lord was called upon him, or that he was called a prophet of the Lord: this he looked upon as a high honour done him; and what still more increased his joy was, that he was a prophet, not of Baal, that could not hear nor help his prophets and worshippers; but of the Lord God of hosts and armies, who was able to uphold him, protect and defend him, against his enemies.