Adam Clarke on Jeremiah 20:9

I wilt not make mention of him - I will renounce the prophetic office, and return to my house.

As a burning fire shut up in my bones - He felt stings of conscience for the hasty and disobedient resolution he had formed; he felt ashamed of his own weakness, that did not confide in the promise and strength of God; and God's word was in him as a strongly raging fire, and he was obliged to deliver it, in order to get rid of the tortures which he felt from suppressing the solemn message which God had given. It is as dangerous to refuse to go when called, as it is to run without a call. On this subject, see on Jer 1:6 (note).