The sign of circumcision (shmeion peritomh). It is the genitive of apposition, circumcision being the sign. A seal of the righteousness of the faith (spragida th dikaiosunh th pistew). Spragi is old word for the seal placed on books ( Revelation 5:1 ), for a signet-ring ( Revelation 7:2 ), the stamp made by the seal ( 2 Timothy 2:19 ), that by which anything is confirmed ( 1 Corinthians 9:2 ) as here. The circumcision did not convey the righteousness, but only gave outward confirmation. It came by faith and "the faith which he had while in uncircumcision" (th en th akrobustiai), "the in the state of uncircumcision faith." Whatever parallel exists between baptism and circumcision as here stated by Paul argues for faith before baptism and for baptism as the sign and seal of the faith already had before baptism. That he might be (ei to einai auton). This idiom may be God's purpose (contemplated result) as in ei to logisqhnai below, or even actual result (so that he was) as in 1 Corinthians 1:20 . Though they be in uncircumcision (di akrobustia). Simply, "of those who believe while in the condition of uncircumcision."