Tertullian — on Gal 2:4 (Against Marcion Book V)

“Therefore he says: "Because of false brethren unawares brought in, who came in privily to spy out our liberty which we have in Christ, that they might bring us into bondage, to whom we gave place by subjection not even for an hour." Let us only attend to the clear sense and to the reason of the thing, and the perversion of the Scripture will be apparent.”