Milton is alerting us to the significance of the word "first" in the very first line, in this wonderful act of violating the laws of iambic pentameter.

弥尔顿在第一句就促使我们注意到“,“初/先“一词的重要性,不惜违背了抑扬格五音步诗的格律。

耶鲁公开课 - 弥尔顿课程节选

Think, in "Birches," of really the extraordinary play of language, the freedom of association, all of which is being played off of the strict demands of the meter, at every moment.

想想，“桦树“，是无与伦比的对语言的把玩，自由的结合，所有这些都在格律诗严格的要求下自由地被使用着，每时每刻。

耶鲁公开课 - 现代诗歌课程节选