In 2 Cor 3:13 Paul says that “Moses put a veil over his face to prevent Israel from seeing the end of what was passing away.” What exactly was it that Israel couldn’t see? The answer: Israel had a hermeneutical problem. She couldn’t see the purpose of the Mosaic covenant. Here I’ll try to prove this reading in two steps.
First, “what was passing away” is simply another way of talking about the old (or Mosaic) covenant. (1) In vv. 7–11, Paul says that the “ministry that brought death” (v. 7) was less glorious than “the ministry of the spirit” (v. 8) for two reasons. It condemned and was “transitory”; whereas “the ministry of the spirit” justifies and “remains” (see vv. 9, 11). The participle translated “what was transitory” in v. 11 is the same participle used in v. 13 and translated “what was passing away,” which, along with their agreement in gender (i.e., both neuter), suggests both refer to the same thing, namely, “the ministry that brought death” in v. 7. Or, to put it all this another way, I suspect that had Paul reversed the comparisons of vv. 9 and 11, v. 13 would have read like this, “We are not like Moses, who put a veil over his face to prevent the Israelites from seeing the end of that which condemns.” In short, “what was passing away” in v. 13 was “the ministry that brought death” in v. 7. (2) This “ministry that brought death” is said in v. 7 to have been “engraved in letters on stone,” which is nearly identical to the description of the (implied) covenant in v. 6, which is there contrasted with the “new covenant.” Thus, the covenant “of the letter,” which “kills,” in v. 6 and “the ministry that brought death” and is “engraved in letters on stone” in v. 7 is the Mosaic or old covenant. This reading is confirmed by the parallelism of vv. 13 and 14, where “what is passing away” in v. 13 is parallel with “the old covenant” in v. 14.
Second, “the end” of the old covenant refers to the goal or point of the old covenant. (1) The veil in v. 13 is said to prevent Israel from seeing the “end” of the old covenant and, in vv. 14–15, this veil is said to remain whenever the old covenant is read, implying that the veil is equivalent to a hermeneutical barrier. (This barrier, Paul makes clear in v. 14, is, fundamentally, moral.) Thus, Israel, due to sin, is prevented from understanding the old covenant and, specifically, from understanding its goal or point. (2) In light of what Paul says in vv. 9 and 11, the goal or point of the old covenant that Israel was unable to see was the old covenant’s temporary, condemning function. Israel, in other words, was prevented from seeing the old covenant’s glory, which is precisely what the veil (implied) in v. 7 hid and what is revealed, according to vv. 16–18, when the veil is removed.
Thus, to say it again, Paul says here in 2 Cor 3:7–18 that Israel had a hermeneutical problem, owing to sin: she wasn’t able to see the purpose of her covenant. All this, therefore, is closely related to what Paul says in Rom 9:30–10:21 and Gal 3:1–4:7 and, moreover, is one of the key differences between the way Paul read Scripture before and after his encounter with the risen Lord on the road to Damascus. (See here for a similar reflection.)