וְכָשְׁל֧וּ אִישׁ־בְּאָחִ֛יו כְּמִפְּנֵי־חֶ֖רֶב וְרֹדֵ֣ף אָ֑יִן וְלֹא־תִֽהְיֶ֤ה לָכֶם֙ תְּקוּמָ֔ה לִפְנֵ֖י אֹֽיְבֵיכֶֽם׃
And they shall stumble one upon another, as it were before the sword, when none pursueth; and ye shall have no power to stand before your enemies.
Read kabbalistic (mystical) interpretation of Leviticus 26:37: and classical mystical sources.