Pages from Merrill's Journal, Special Collections, Washington University Libraries, Folder 2906: JNL 66, 1961: October 10 - 1963: October 23.
From Langdon Hammer, James Merrill: Life and Art: "The evidence of Merrill’s letters and the dating of his work sheets for 'The Thousand and Second Night' show that most of the poem was written in fall 1962, starting in September, although some drafts reach back as far as 1960, and the section called 'Rigor Vitae' was begun in April" (346).
In Manuscript 1 Merrill's reference to an "orgy, 'This is my body. Eat this . . .,'" refers to Luke 22:19, when Jesus, speaking to his apostles, "took bread, gave thanks and broke it, and gave it to them, saying, 'This is my body given for you; do this in remembrance of me.'" See also Matthew 26:26-29: "While they were eating, Jesus took bread, gave thanks and broke it, and gave it to his disciples, saying, 'Take and eat; this is my body.'"