These terms occur as a pair in oharae no kotoba (the great purification incantation) described in 'Norito' (incantations) in Fascicle (Book) 8 of the "Engishiki" (an ancient book for codes and procedures on national rites and prayers).
『延喜式』巻八「祝詞」に収録される大祓詞に対句として登場する。