Dighanikaya 14.40

14.40

Vipassīti ettha ayaṃ vacanattho, antarantarā nimīlajanitandhakāravirahena visuddhaṃ passati, vivaṭehi ca akkhīhi passatīti vipassī; dutiyavāre viceyya viceyya passatīti vipassī; vicinitvā vicinitvā passatīti attho.

As for "Vipassī": here this is the meaning of the word: because he sees clearly, free from the darkness produced by blinking in between, and sees with wide-open eyes, he is Vipassī. In the second instance: because he sees having investigated again and again, he is Vipassī; the meaning is: having scrutinized again and again, he sees.