The Upanishads, Part 1 (SBE01)
Chapters
Kena-Upanishad: First Adhyaya: Third Khanda

^163:1 Dasinritya-bahubhutamaithuna-brahmakaripumskalisamprava-dadikam. See Rajendralal Mitra, Introduction to his edition of the Aitareya-aranyaka, p. 25. It might be better to join ekahah with santyam, but even then the argumentation is not quite clear.