Ezra 2:11 Kabbalah

בְּנֵ֣י בֵבָ֔י שֵׁ֥שׁ מֵא֖וֹת עֶשְׂרִ֥ים וּשְׁלֹשָֽׁה׃ (ס)

The children of Bebai, six hundred twenty and three.

Read kabbalistic (mystical) interpretation of Ezra 2:11: and classical mystical sources.