וְנָסַ֗ע דֶּ֚גֶל מַחֲנֵ֣ה בְנֵי־דָ֔ן מְאַסֵּ֥ף לְכָל־הַֽמַּחֲנֹ֖ת לְצִבְאֹתָ֑ם וְעַל־צְבָא֔וֹ אֲחִיעֶ֖זֶר בֶּן־עַמִּישַׁדָּֽי׃
And the standard of the camp of the children of Dan, which was the rearward of all the camps, set forward according to their hosts; and over his host was Ahiezer the son of Ammishaddai.
Read kabbalistic (mystical) interpretation of Numbers 10:25: and classical mystical sources.