Philippians 3:5

‘Circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, a Hebrew of Hebrews,'

Paul now lists the things that had marked him off as ‘perfect' in the eyes of the Jews. He had been properly circumcised at the right time, he could trace his descent backwards to prove that he was a genuine true-born Israelite (which, in spite of their best efforts, comparatively few Jews could do), he was a recognised member of the tribe of Benjamin, one of the tribes which had preserved its wholeness and identity and had remained faithful to Jerusalem all the way through, and he was brought up strictly as a Hebrew and Aramaic speaking Jew, being born of Hebrew parents. He had all the right credentials.