Rashi on Exodus 14:3/רש"י על שמות י״ד:ג׳

1ואמר פרעה THEN PHARAOH WILL SAY — when he hears that they are turning back.

2לבני ישראל means על בני ABOUT THE CHILDREN OF ISRAEL. Similarly. (v. 14) “The Lord will fight לכם”, i. e. עליכם for you; (Genesis 20:13) “Say לי, he is my brother” i. e. say about me.

3נבכים הם means, shut up and sunk deep. old French serrer. Of similar meaning are (Job 38:16) “the depths of (נבכי) the sea”; (Psalms 84:7) “in the vale of dejection (הבכא)”; (Job 28:11) “from the depths (מבכי) of the rivers.”

4נבכים הם means THEY ARE SHUT UP in the wilderness — so that they do not know how to get out of it and whither they should go.