There are three major alternatives for understanding the last phrase of Hebrews 10:20: τοῦτ᾿ ἔστιν τῆς σαρκὸς αὐτοῦ (“that is, his flesh”). The first is reflected in most standard English translations (ESV, KJV, NASB, NIV, NKJV, NRSV, RSV). It understands the veil that separated the holy place from the most holy place in the OT tabernacle to be typical of the physical body of Christ—the new, antitypical sacrifice that has provided access. Taken in this way the antecedent of σαρκός is καταπετάσματος earlier in the verse.
Lane argues for a different understanding in which the phrase “introduces a clause explicative of the preceding sentence as a whole.” This he supports by an appeal to the parallel structure of vv. 19 and 20 in which each verse speaks of “the new way, its goal, and the sacrificial death of Jesus as the basis for entrance” (Lane, Hebrews, WBC, 2:275). He would translate: “we have authorization for free access … by means of the blood of Jesus … which he made available for us through the curtain (that is to say, by means of his flesh)” (273).
The third alternative understands σαρκός as referring to ὁδόν. It would be translated, “the new, living way which he has opened for us through the curtain, [that is] the way of his flesh” (NEB, REB). This would refer the antecedent of σαρκός, not to the immediately preceding substantive καταπετάσματος, but to the second preceding substantive (ὁδόν). Such a pattern also appears in 7:5 and 13:15. This position is taken by Westcott and by Montefiore (both ad loc). This is an attractive solution to a somewhat awkward statement. Unfortunately, grammar makes it highly unlikely.
A key factor in evaluating the alternatives above is the syntactical pattern of the idiomatic phrase τοῦτ᾿ ἔστιν.# “Greek has a special explanatory idiom in which the word or cluster following τοῦτ᾿ ἔστιν or ὅ ἔστιν usually agrees in gender, number and case with the word or word cluster for which it is the explanation or interpretation” (McGaughy, Descriptive Analysis/Εἶναι, 117–18)* Based on its use in the NT, this rule can be stated more precisely: whenever there is an explicit antecedent (i.e., there is a specific word that serves as the antecedent; some occurrences of the phrase τοῦτ᾿ ἔστιν have a general antecedent in which some phrase or concept serves as the antecedent rather than a specific word), the word following τοῦτ᾿ ἔστιν always agrees with its antecedent in case and almost always in gender and number.† When the two words are both nouns, agreement in gender is not always possible since nouns have fixed gender; when one of the words is a pronoun, adjective, or participle, they usually agree in gender.§
This makes the association of σαρκός with ὁδόν very unlikely. The only alternatives are the traditional view (καταπετάσματος as the antecedent of σαρκός) or Lane’s suggestion that the antecedent is the entire sentence. A general antecedent is grammatically possible with τοῦτ᾿ ἔστιν (see the examples cited in note † at the end of this article). Such an explanation, however, seems to be forced when there is an explicit antecedent in close proximity with which σαρκός agrees in gender, number, and case. From a grammatical perspective it thus appears that the traditional view is correct.
Notes
# BDF §132.2 points out that τοῦτ᾿ ἔστιν is literary whereas ὅ ἔστιν is vernacular. The phrase τοῦτό ἐστιν functions, not as an idiomatic, transitional phrase, but as a normal subject/predicate sentence.
* Robertson’s comment that it “has no regard to case, number, or gender” refers to the form of τοῦτ᾿, not to the word that follows ἔστιν (Grammar, 412; cf. 705; cf. BDF, §132.2).
† The following occurrences of τοῦτ᾿ ἔστιν have an explicit antecedent with which the phrase following agrees in case: Mark 7:2, χερσίν, τοῦτ᾿ ἔστιν ἀνίπτοις; Acts 1:19, Ἁκελδαμάχ, τοῦτ᾿ ἔστιν χωρίον αἵματο; 19:4, τὸν ἐρχόμενον … τοῦτ᾿ ἔστιν εἰς τὸν Ἰησοῦν; Rom 7:18, ἐν ἐμοί, τοῦτ᾿ ἔστιν ἐν τῇ σαρκί μου; 10:8, τὸ ῥῆμά…, τοῦτ᾿ ἔστιν τὸ ῥῆμα τῆς πίστεως; Phlm 12, ὅν…, τοῦτ᾿ ἔστιν τὰ ἐμὰ σπλάγχνα; Heb 2:14, τὸν τὸ κράτος ἔχοντα τοῦ θανάτου, τοῦτ᾿ ἔστιν τὸν διάβολον; 7:5, τὸν λαόν…, τοῦτ᾿ ἔστιν τοὺς ἀδελφοὺς αὐτῶν; 9:11, σκηνῆς…, τοῦτ᾿ ἔστιν οὐ ταύτης τῆς κτίσεως; 11:16, κρείττονος…, τοῦτ᾿ ἔστιν ἐπουρανίου; 13:15, θυσίαν…, τοῦτ᾿ ἔστιν καρπὸν χειλέων; 1 Pet 3:20, ὀλίγοι, τοῦτ᾿ ἔστιν ὀκτὼ ψυχαί. The following occurrences of τοῦτ᾿ ἔστιν have a general antecedent (a phrase or a concept) and thus there is nothing on which to base grammatical agreement: Matt 27:46, ηλι ηλι λεμα σαβαχθανι; τοῦτ᾿ ἔστιν· θεέ μου θεέ μου, ἱνατί με ἐγκατέλιπες; Acts 2:16, ἀλλὰ τοῦτό ἐστιν τὸ εἰρημένον διὰ τοῦ προφήτου Ἰωήλ; Rom 9:8, τοῦτ᾿ ἔστιν, οὐ τὰ τέκνα τῆς σαρκὸς ταῦτα τέκνα τοῦ θεοῦ ἀλλὰ τὰ τέκνα τῆς ἐπαγγελίας λογίζεται εἰς σπέρμα; 10:6–7, μὴ εἴπῃς ἐν τῇ καρδίᾳ σου· τίς ἀναβήσεται εἰς τὸν οὐρανόν; τοῦτ᾿ ἔστιν Χριστὸν καταγαγεῖν· ἤ· τίς καταβήσεται εἰς τὴν ἄβυσσον; τοῦτ᾿ ἔστιν Χριστὸν ἐκ νεκρῶν ἀναγαγεῖν.
§ The only instance in which they do not agree in gender is Phlm 12. The same text also varies the number, but this is due to an idiomatic expression that is always plural (τὰ ἐμὰ σπλάγχνα). The only other instance of a variation in number is Heb. 7:5 due to one of the words being a collective term.
The note above is slightly revised and corrected from a paragraph that appears in my article, “The Exhortations of Hebrews 10:19-25,” JMAT 6.1 (spring 2002): 44-62. [I don't have the published copy at hand, so I can't reference the exact page.]