יְהוָ֤ה אֱלֹֽהֵיכֶם֙ הַהֹלֵ֣ךְ לִפְנֵיכֶ֔ם ה֖וּא יִלָּחֵ֣ם לָכֶ֑ם כְּ֠כֹל אֲשֶׁ֨ר עָשָׂ֧ה אִתְּכֶ֛ם בְּמִצְרַ֖יִם לְעֵינֵיכֶֽם׃
The LORD your God who goeth before you, He shall fight for you, according to all that He did for you in Egypt before your eyes;
Read halakhic rulings (Jewish law) on Deuteronomy 1:30: and classical halakhic sources.