וַיֹּ֤אמֶר אֱלֹהִים֙ אֶל־אַבְרָהָ֔ם וְאַתָּ֖ה אֶת־בְּרִיתִ֣י תִשְׁמֹ֑ר אַתָּ֛ה וְזַרְעֲךָ֥ אַֽחֲרֶ֖יךָ לְדֹרֹתָֽם׃
And God said unto Abraham: ‘And as for thee, thou shalt keep My covenant, thou, and thy seed after thee throughout their generations.
Read kabbalistic (mystical) interpretation of Genesis 17:9: and classical mystical sources.