נֵ֣ר יְ֭הוָה נִשְׁמַ֣ת אָדָ֑ם חֹ֝פֵ֗שׂ כָּל־חַדְרֵי־בָֽטֶן׃
人的靈魂是永恆者的燈，鑒察人心腹中的一切隱密深處。
Tosefta Pesachim
On the evening of the fourteenth, we check for chamets by candlelight, not by sunlight, not by moonlight, but rather only by candlelight (since the candlelight is greater). Even though there's no explicit proof for this, it's a remembrance for that which is discussed (Tzefaniah 1) "And in that time I will look through Jerusalem by candle" and that which it says (Proverbs 20) "The candle of God is a human soul".