Charles Ellicott Commentary Romans 16:17

"Now I beseech you, brethren, mark them that are causing the divisions and occasions of stumbling, contrary to the doctrine which ye learned: and turn away from them." — Romans 16:17 (ASV)

Cause divisions and offences.—Set traps in the way of the unsuspecting, so as to entice them into false doctrine and schismatic practices.

On Romans 16:17-20:

The Epistle would naturally end here, but an afterthought occurs to the Apostle. His experience of other churches, especially those at Corinth and in Galatia, suggests to him that he should warn his readers against false teachers, though such teachers had not yet gained a strong hold among them.