I found this paragraph from John Sailhamer in his commentary on Genesis for the Expositors Bible Commentary (V.2, pp. 12-13) worth sharing:

“It is important to see that while the Pentateuch is about the Sinai covenant, it is not the document of that covenant. The Pentateuch does contain documents that were part of the Sinai covenant, e.g. the Ten Commandments (Exod 20), the covenant code (Exod 21-23), the tabernacle instruction (Exod 25-31), the law of sacrifice (Lev 1-7); but the Pentateuch, as a literary document, is fundamentally different from the document of the Sinai covenant. What this means is that the Pentateuch is a document that looks at the Sinai covenant as an object under consideration. It was attempting to evaluate the Sinai covenant from the perspective that was not the same as that of the covenant itself. Like the other historical books of the OT, the Prophets, and the NT, the Pentateuch represents a look back at the failure of Sinai and a look forward to a time of fulfillment (e.g., Deut 30).”