אַל־תַּאֲמִ֣ינוּ בְרֵ֔עַ אַֽל־תִּבְטְח֖וּ בְּאַלּ֑וּף מִשֹּׁכֶ֣בֶת חֵיקֶ֔ךָ שְׁמֹ֖ר פִּתְחֵי־פִֽיךָ׃
너희는 이웃을 믿지 말며 친구를 의지하지 말며 네 품에 누운 여인에게라도 네 입의 문을 지킬지어다
Rashi
Believe not a friend [This is to be understood] according to its apparent meaning. But our Sages explained it as referring to the Most High. Do not sin and say that the Holy One, blessed be He, is our Friend, and He will forgive us. [from Hagiga 16a]
Rashi
the openings of your mouth Heb. פִּתְחֵי. The words of your mouth, the openings of your mouth.