With Donne, whose muse on dromedary trots,
Wreathe iron pokers into true-love knots;
Rhyme's sturdy cripple, fancy's maze and clue,
Wit's forge and fire-blast, meaning's press and screw.
Coleridge was an exception to the rule of his times in many ways, and among those ways is his admiration of John Donne's poetry. For more of the 18th and 19th centuries, his poetry was scorned as crude and unskilled in execution. Today, we hold him much higher regard, and Coleridge did as well. In these scant four lines, he expresses his appreciation of Donne's poetry in a series of fantastical images.
Donne's poetry can take hoot iron pokers and fashion them into "true-love knots." To me, that means that Donne takes the difficult and makes it artful and elegant with apparent ease. The images of the poem are largely paradoxical, as well, mimicking the late Renaissance fashion in which Donne wrote. "Sturdy cripple" in particular stands out as paradox. The rest of the lines refer to how Donne coaxed meaning out of words. His wit was a forge, firing ideas into shape, using a press screw to fashion meaning. We get a real sense of the work that must've gone into Donne's poetry with these images, and Coleridge presents him as an expert craftsmen, something which was contrary to the general consensus at Coleridge's time.