תְּנוּ֩ לַיהוָ֨ה אֱלֹהֵיכֶ֤ם כָּבוֹד֙ בְּטֶ֣רֶם יַחְשִׁ֔ךְ וּבְטֶ֛רֶם יִֽתְנַגְּפ֥וּ רַגְלֵיכֶ֖ם עַל־הָ֣רֵי נָ֑שֶׁף וְקִוִּיתֶ֤ם לְאוֹר֙ וְשָׂמָ֣הּ לְצַלְמָ֔וֶת ישית [וְשִׁ֖ית] לַעֲרָפֶֽל׃
Give glory to the LORD your God, Before it grow dark, And before your feet stumble Upon the mountains of twilight, And, while ye look for light, He turn it into the shadow of death, And make it gross darkness.
Rashi on Jeremiah
and before your feet stumble Heb. יתנגפו (achopper in French), to stumble.
Rashi on Jeremiah
the dark mountains Heb. נשף, the dark mountains when they go into exile.
Rashi on Jeremiah
and making it into a thick cloud Heb. ושית, like ולשית, and to make the light into a thick cloud.