Plath structured “Lady Lazarus” around the number three. Iterations of this number appear everywhere in the poem, in ways both formal and thematic. Perhaps most obvious is Plath’s use of three-line stanzas, also called “tercets.” Plath’s choice to use tercets recalls the unique stanza form innovated by Dante Alighieri for his fourteenth-century Italian masterpiece, The Divine Comedy. Dante developed a verse form known as terza rima, which consisted of tercets linked together through an interlocking rhyme scheme: ABA BCB CDC and so on. Although Plath doesn’t adopt this rhyme scheme, her use of tercets is at least reminiscent of Dante’s verse, which remains the best-known example of a poem written in three-line stanzas. If this connection between Plath and Dante seems strained, consider the extent to which “Lady Lazarus” draws on biblical images and themes. In particular, consider the closing image of the speaker’s body being burned, then rising from the ash. This image certainly references the phoenix, a mythological bird that occasionally burns to ash then resurrects itself. But the image also echoes Dante’s journey through the three realms of the Christian afterlife, which descends to Hell before rising through Purgatory and Paradise.

In addition to the tercet stanza form, Plath invokes the number three in more thematic ways. For instance, the speaker organizes her narrative around three suicide attempts. As she states in the opening stanza, she has attempted suicide “one year in every ten” (line 2), and the fact that she recently turned thirty means she was due for her third go (lines 20–24):

     I am only thirty.
     And like the cat I have nine times to die.

     This is Number Three
     What a trash
     To annihilate each decade.

Note the multiples of three that appear throughout this passage: “thirty,” “nine times to die,” “Number Three.” Aside from the importance of the number three in relation to the speaker’s suicide attempts, the number also relates to the speaker’s twisted invocation of the Christian notion of the Holy Trinity. In traditional theology, the Holy Trinity consists of God the Father, Christ the Son, and the Holy Ghost. In “Lady Lazarus,” however, the speaker invokes a sort of Unholy Trinity. This altered Trinity consists of three representatives of patriarchy: God, the Devil, and the doctor who has helped thwart her suicide attempt. She refers to each of these figures in the poem’s closing stanzas: “Herr God, Herr Lucifer” (line 79), and “Herr Doktor” (line 65).