וּבֶן־שְׁמֹנַ֣ת יָמִ֗ים יִמּ֥וֹל לָכֶ֛ם כָּל־זָכָ֖ר לְדֹרֹתֵיכֶ֑ם יְלִ֣יד בָּ֔יִת וּמִקְנַת־כֶּ֙סֶף֙ מִכֹּ֣ל בֶּן־נֵכָ֔ר אֲשֶׁ֛ר לֹ֥א מִֽזַּרְעֲךָ֖ הֽוּא׃
And he that is eight days old shall be circumcised among you, every male throughout your generations, he that is born in the house, or bought with money of any foreigner, that is not of thy seed.
Read kabbalistic (mystical) interpretation of Genesis 17:12: and classical mystical sources.