Vaikhānasamantrapraśna, 5-8 · Chapter 5.1.21

rúdrā́-jam ā́vāhayāmi

apám[*42] ā́vāhayāmi

ā́pá-vátsam ā́vāhayāmi

ī́śam ā́vāhayāmi

párjányam ā́vāhayāmi

jáyántam ā́vāhayāmi

ā́dítyam ā́vāhayāmi

mā́héndram ā́vāhayāmi[*43]

sátyákam ā́vāhayāmi

bhŕ̥śam ā́vāhayāmi
[*42] The word ap, “water”, is here used in the singular accusative. The singular form of this word is normally found only in Vedic Sanskrit.
[*43] mahendram āvaha: TB 3.5.3.2, ŚŚ 1.5.3.