俱舍論記 8.163

8.163

若「此契經至何現在前」者，第二健達縛經。健達名香，縛名食，即中有名。謂具三緣方入母胎：一母身調適，謂無乾、濕二疾；二交愛現前，謂俱起貪；三健達縛現前，謂中有起。意取第三證有中有。

Regarding "If this discourse [...] how could it be present before one?": this is the second, the Gandharva-sūtra. Gandha means fragrance, and arva means consumer; this is another name for the intermediate existence. That is, having three conditions complete, one then enters the mother's womb: first, the mother's body is properly regulated, meaning she is free of the two ailments of dryness and dampness; second, sexual union is present, meaning both arouse desire; third, the gandharva is present, meaning the intermediate existence arises. The intention is to take the third to prove that intermediate existence exists.