Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 18:13-17, 19-23.
Things were so bad in Judah, they even attacked Jeremiah. To attack Yahweh's prophet was to attack Yahweh himself. (See: [[rc://en/tw/dict/bible/kt/prophet]])
Like a potter can change what he is making from one type of pot to another, God can change his plans and not punish people if they repent. The image of God as a potter and mankind as clay is an important one in Scripture. (See: [[rc://en/tw/dict/bible/kt/repent]] and [[rc://en/ta/man/jit/figs-simile]])