It comprises three strophes of four verses in Classical iambic dimeter together with a fourth concluding strophe ( or doxology ) in unrhymed verses varying for the season .
Three strophes of four verses in Classical iambic dimeter are the verses rhyming in couplets .
It comprises three strophes of four verses in Classical iambic dimeter , the verses rhyming in couplets , together with a fourth concluding strophe ( or doxology ) in unrhymed verses varying for the season .