וְגַם־עֵ֥רֶב רַ֖ב עָלָ֣ה אִתָּ֑ם וְצֹ֣אן וּבָקָ֔ר מִקְנֶ֖ה כָּבֵ֥ד מְאֹֽד׃
중다한 잡족과 양과 소와 심히 많은 생축이 그들과 함께하였으며
Zohar
Erev/night - as you say "and also an erev rav went up with them" (Ex. 12:38), since all those pure travails are the ones that mix [mit'arev] with the forces of the night. And this is why there is no obligation regarding the night prayer, because no person can say it like Ya'akov, who was the master of the dwelling, and was the [only] one who could say it properly.