The other sources which I have posted already speak of an obviously symbolic meaning; which you say must mean both.
Regardless, Tertullian does clarify that it isn’t meant to be taken literally.
Oh really?
"Then, having taken the bread and given it to His disciples, He made it His own body, by saying, “This is my body,” that is, the figure of my body. A figure, however, there could not have been, unless there were first a veritable body. (Tertullian, Against Marcion, 4.)
More specifically, that quote comes from Chapter 40 of Book IV of Against Marcion. In context, it turns out that Tertullian is actually arguing that the Real Presence of Christ in the Eucharist and Christ’s Death on the Cross both disprove the Gnostics’ claim that Christ didn’t actually come in the Flesh (since, if they were right, we wouldn’t have the Eucharist or the Atonement). [Tertullian isn’t the first to make this particular argument, either: Ignatius of Antioch, one of the Apostle John’s students, made the same argument in the early 100s: the Gnostics’ beliefs lead them to deny the Eucharist, so we know that they’re wrong.] In the midst of this, Tertulilan explains why Christ chose to consecrate bread and wine, instead of a melon:
When He so earnestly expressed His desire to eat the passover, He considered it His own feast; for it would have been unworthy of God to desire to partake of what was not His own. Then, having taken the bread and given it to His disciples, He made it His own body, by saying, “This is my body,” that is, the figure of my body. A figure, however, there could not have been, unless there were first a veritable body. An empty thing, or phantom, is incapable of a figure. If, however, (as Marcion might say,) He pretended the bread was His body, because He lacked the truth of bodily substance, it follows that He must have given bread for us. It would contribute very well to the support of Marcion’s theory of a phantom body, that bread should have been crucified! But why call His body bread, and not rather (some other edible thing, say) a melon, which Marcion must have had in lieu of a heart! He did not understand how ancient was this figure of the body of Christ, who said Himself by Jeremiah: “I was like a lamb or an ox that is brought to the slaughter, and I knew not that they devised a device against me, saying, Let us cast the tree upon His bread,” which means, of course, the cross upon His body. And thus, casting light, as He always did, upon the ancient prophecies, He declared plainly enough what He meant by the bread, when He called the bread His own body.
He likewise, when mentioning the cup and making the new testament to be sealed “in His blood,” affirms the reality of His body. For no blood can belong to a body which is not a body of flesh. If any sort of body were presented to our view, which is not one of flesh, not being fleshly, it would not possess blood. Thus, from the evidence of the flesh, we get a proof of the body, and a proof of the flesh from the evidence of the blood. …]Thus did He now consecrate His blood in wine, who then (by the patriarch) used the figure of wine to describe His blood.
So let’s recap Tertullian’s arguments:
Marcion denied that Christ had a true Body of Flesh and Blood. If that were true, then we would have to believe that the Eucharist was just bread, and that Christ on the Cross was just bread.
He says that Christ explained exactly what He meant by “Bread” when He described it as His Body. According to Tertullian, the question now is why Christ referred to His Body as “Bread,” rather than something else (like a melon). He answers this by saying that Christ’s Body is referred to throughout Scripture as Bread.
He quotes a passage from the Septuagint version of Jeremiah to show that Christ’s Crucified Body is rightly called “Bread.”
The Eucharistic Bread and Wine affirm the reality of Christ’s Flesh, since He couldn’t give us His Body or Blood if He didn’t have actual Flesh. Christ’s Flesh, in turn, proves that He had a true Body.
Christ consecrates the wine, fulfilling the Old Testament typology.
catholicdefense.blogspot.com/2014/02/did-tertullian-deny-real-presence.html?m=1