For that ye ought to say (ἀντὶ τοῦ λέγειν ὑμᾶς)
Jam 4:14 was parenthetical, so that at this point the thought is taken up from Jam 4:13 : Ye who say we will go, etc. - for that ye ought to say. The rendering in margin of Rev. is simpler: instead of your saying.