דֶּ֣גֶל מַחֲנֵ֥ה אֶפְרַ֛יִם לְצִבְאֹתָ֖ם יָ֑מָּה וְנָשִׂיא֙ לִבְנֵ֣י אֶפְרַ֔יִם אֱלִישָׁמָ֖ע בֶּן־עַמִּיהֽוּד׃
On the west side shall be the standard of the camp of Ephraim according to their hosts; the prince of the children of Ephraim being Elishama the son of Ammihud,
Read kabbalistic (mystical) interpretation of Numbers 2:18: and classical mystical sources.