I Chronicles 12:38 Kabbalah

וּמֵעֵ֣בֶר לַ֠יַּרְדֵּן מִן־הָראוּבֵנִ֨י וְהַגָּדִ֜י וַחֲצִ֣י ׀ שֵׁ֣בֶט מְנַשֶּׁ֗ה בְּכֹל֙ כְּלֵי֙ צְבָ֣א מִלְחָמָ֔ה מֵאָ֥ה וְעֶשְׂרִ֖ים אָֽלֶף׃

And on the other side of the Jordan, of the Reubenites, and the Gadites, and of the half-tribe of Manasseh, with all manner of instruments of war for the battle, a hundred and twenty thousand.

Read kabbalistic (mystical) interpretation of I Chronicles 12:38: and classical mystical sources.