Have been made (eisin gegonotes). Periphrastic perfect active indicative of ginomai (perfect active participle of ginomai) and then eisin. The parenthesis runs from hoi men gar (for they) to eis ton aiōna (for ever, end of Heb 7:21).
But he with an oath (ho de meta horkōmosias). Positive statement in place of the negative one in Heb 7:20.