Citation 2: [L=175517] rasa N. of the sacred syllable, “Om,” S3a1n3khGr2.

Where in शाङ्खायन-गृह्य-सूत्र is the word ‘rasa’ used for Om? I searched in the digital version of Bloomfield’s Concordance but did not find it.

Compare the following entry in Otto Böhtlingk's "Sanskrit-Wörterbuch in kürzerer Fassung", s.v. rasa [5-173] 1)  y) "Bez. der heiligen Silbe om Śāṅkh. Gṛhy. 2,13". (refers to the edition by Hermann Oldenberg published in Albrecht Weber's "Indische Studien" vol. 15, 1878; for a digital version, see https://archive.org/details/indischestudien00unkngoog ; you will find the relevant textual passage on p. 62: vāruṇya 'rcā rasena vā; German translation: p. 63: "mit einem Varuṇaverse oder dem Saft(-spruch Om)"; note: p. 141: "[...] vedānāṃ rasabhūtena praṇavena").

Best wishes,
Roland Steiner