Thinketh to have confidence (dokei pepoiqenai). Second perfect active infinitive. Old idiom, "seems to himself to have confidence." Later idiom like Matthew 3:9 "think not to say" and 1 Corinthians 11:16 , "thinks that he has ground of confidence in himself." I yet more (egw mallon). "I have more ground for boasting than he" and Paul proceeds to prove it in the rest of verses 1 Corinthians 56 . Circumcised the eighth day (peritomh oktahmero). "In circumcision (locative case) an eighth day man." Use of the ordinal with persons like tetartaio ( John 11:39 ). Ishmaelites were circumcised in the thirteenth year, proselytes from Gentiles in mature age, Jews on the eighth day ( Luke 2:21 ). Of the stock of Israel (ek genou Israhl). Of the original stock, not a proselyte. Benjamin (Beniamin). Son of the right hand (that is, left-handed), son of Rachel. The first King, Saul (Paul's own Hebrew name) was from this little tribe. The battle cry of Israel was "After thee, O Benjamin" ( Judges 5:14 ). A Hebrew of the Hebrews (Ebraio ex Ebraiwn). Of Hebrew parents who retained the characteristic qualities in language and custom as distinct from the Hellenistic Jews ( Acts 6:1 ). Paul was from Tarsus and knew Greek as well as Aramaic ( Acts 21:40 ; Acts 22:2 ) and Hebrew, but he had not become Hellenized. A Pharisee (Parisaio). In distinction from the Sadducees ( Galatians 1:14 ) and he continued a Pharisee in many essential matters like the doctrine of the resurrection ( Acts 23:6 ). Cf. 2 Corinthians 11:22 .