Romans 14:23

Dionysius Extant Fragments Part I

in this matter or not. And he that doubteth in the matter of meats, the apostle tells us, "is damned if he eat."[164]

Origen Commentary on Matthew Book XI

as for us who know that some things are used by demons, or if we do not know, but suspect, and are in doubt about it, if we use such things, we have used them not to the glory of God, nor in the name of Christ; for not only does the suspicion that things have been sacrificed to idols condemn him who eats, but even the doubt concerning this; for "he that doubteth," according to the Apostle, "is condemned if he eat, because he eateth not of faith; and whatsoever is not of faith is sin."[103]

Origen Commentary on Matthew Book XI

And the saying is I think, not to be despised, and on this account, demands clear exposition, which seems to me to be thus; as it is not the meat but the conscience of him who eats with doubt which defiles him that eateth, for "he that doubteth is condemned if he eat, because he eateth not of faith,"[136]