What does Hebrews 8:3 mean?

Earlier passages referred to Jesus' role as a priest, offering sacrifice on behalf of mankind (Hebrews 6:19–20). This was part of an explanation of how Jesus' priesthood, symbolized by Melchizedek, is superior to that of the Levitical priests. Here, in chapter 8, the idea is being applied to the new covenant, as opposed to the old covenant of the Levitical priesthood. Interestingly, the sacrifices of the existing Levitical priests are described as plural: "gifts and sacrifices." As a priest, Jesus must have "something"—translated "somewhat" in the KJV—to offer God. This word, however, is singular. This implies a difference between the two, namely that Jesus' sacrifice for sin is a once-and-for-all action. This is a distinction the writer of Hebrews will make again, later in the letter (Hebrews 9:24–26; 10:12).

Along those same lines, the action Jesus takes is described using the word prosenenkē. This is in a Greek tense which implies a past, once-for-all, completed action. The reference to Levitical priests, earlier in the verse, uses the same root word, but with a different tense. That word is prospherein, which is an active, present action.

Putting these two ideas together makes the intent of the original Greek wording that much clearer. Levitical priests "are offering" repeated sacrifices, while Jesus "has offered" a single sacrifice. This passage will continue by providing more details as to why Jesus' sacrifice, and His covenant, are therefore better than the system of Old Testament Law.