Tertullian, Against Marcion 4.12
I will also address the Sabbath upfront: this dispute could never have arisen unless Christ carried the God of the Sabbath within him. After all, no one would have debated why he was destroying the Sabbath if he were actually supposed to destroy it. And he would have been obliged to destroy it only if it belonged to another god; in that case, no one would have been surprised to see him doing what fit that deity. They were astonished, therefore, precisely because it was unfitting for him to bear the Creator God and then assault that God's own Sabbath.
To settle the primary issues once and for all, so we do not keep encountering the same points in every argument the opponent builds on some new institution of Christ, this definition will stand: the dispute centered on the novelty of each institution because nothing had yet been produced about a novelty of divinity. Just as that question was never debated, neither can it be countered from the novelty of the institutions themselves that Christ has sufficiently demonstrated a different divinity. For when the Creator has pronounced that this very novelty is not to be wondered at in Christ, it becomes clear that one must first expound another God and only then introduce his discipline, since God confers authority on discipline, not discipline on God. Unless, of course, Marcion plainly learned such perversions not from a teacher through letters, but from letters through a teacher.
Latin
De sabbato quoque illud praemitto, nec hanc quaesti- onem consistere potuisse, si non deum sabbati circumferret Christus. nec enim disceptaretur, cur destrueret sabbatum, si destruere deberet. porro destruere deberet, si alterius dei esset, nec quisquam miraretur facientem quod illi congruebat. mirabantur ergo, quia non congruebat illi deum creatorem circumferre et sabbatum eius impugnare. et ut prima quaeque decidamus, ne eadem ubique nouemus ad omnem argumentationem aduersarii ex aliqua noua Christi institutione nitentem. haec iam definitio stabit: ideo de nouitate institutionis cuiusque disceptatum, quia de nouitate diuinitatis nihil erat usque adhuc editum, sicuti nec disceptatum ***, nec posse retorqueri ex ipsa nouitate institutionis cuiusque satis aliam a Christo demonstratam diuinitatem, quando et ipsam nouitatem pronuntiatam a creatore constiterit in Christo non esse mirandam et oportuerit utique prius alium deum exponi, postea disciplinam eius induci, quia deus auctoritatem praestet disciplinae, non deo disciplina; nisi si et Marcion plane tam peruersas non per magistrum litteras didicit, sed per litteras magistrum.