In his commentary on the Psalms, Robert Alter refers to "one ancient Greek version, [reading] keveidi, 'my liver,' which he utilizes in his translation of this verse using the word 'heart' instead of 'liver.' I'm unable to uncover that particular manuscript he used in his translation: "O, let my heart hymn You and be not still. . ."
John Brug, in his commentary on the Psalms writes:
In verse 13 כָּבוֹד apparently is a synonym for "my soul." (See the comment on Psalm 16:9)
Ok, so I turn to his commentary on that verse and read:
In the middle of verse 9 the Masoretic text literally reads, "My glory will rejoice." This may be a reference to the soul. However, some manuscripts omit the waw, yielding the reading כְבֵדִי, "my liver." Since in Semitic idiom the liver was thought to be a center of emotion, this reading yields good sense in the context. It is, however, not a common idiom in Biblical Hebrew and usually "liver" refers to bitter feelings rather than happy feelings. The NIV follows the Septuagint reading "tongue" without a textual note to justify this departure from the Hebrew text.
So that, at least, gives us the answer to the question as to why Robert Alter would read "liver" there instead of "glory." The difficulty, of course, is that even though in Psalm 16:9, if one looks in the apparatus, there are some manuscripts that support "liver", in Psalm 30:13, there are no Hebrew manuscripts that support "liver" as a reading.
So, in Psalm 30:13, I would shy away from "liver" because there's no textual support for it. But, as Brug notes, most often "liver" has a negative context rather than a positive one.
In Psalm 30:13 our English versions seemingly either apply the "when in doubt, throw it out" rule (e.g. CSB), or they take it as an almost synonym for the intensive use of נֶפֶשׁ ("heart, whole being, inner most parts, etc.")
It's a very difficult passage. So please understand that I'm not speaking against the choices our English versions have made.
Actually, a number of versions take liberties with Ps 30:12 such as:
- adding the word "heart" (eg, NIV)
- adding the word "my" (eg, NIV, NASB, KJV, NKJV, ESV, etc)
- adding the word "I" (eg, NLT, CSB, etc)
- adding the word "soul" (eg, NASB, which adds a footnote saying that the Hebrew is literally, "glory")
I could not find a version, even among the LXX that uses the word "liver". Thus, in its simplest most literal form, the Hebrew reads:
To the end that glory may sing praise to You and not be silent. O LORD my God, I will give thanks to You forever.
The LXX reads:
ὅπως ἄν ψάλῃ σοι ἡ δόξα μου, καὶ οὐ μὴ κατανυγῶ. Κύριε ὁ θεός μου, εἰς τὸν αἰῶνα ἐξομολογήσομαί σοι. = that my glory may sing praise to thee, and I may not be pierced with sorrow. O Lord my God, I will give thanks to thee for ever. [Note the added "my".]
Ellicott lists some of the reasons that translators have taken such different ideas:
(12) My glory.—The suffix is wanting in the Hebrew, and in all the older versions except LXX. and Vulg. The Chaldee versions make the word concrete and render “the nobles.” The Syriac, reading the verb in a different person, makes glory the object—“then will I sing to thee, Glory.” My glory would, as in Psalm 108:1, mean my heart. (See Note, Psalm 16:9.) Without the pronoun, we must (with Jerome) understand by “glory” renown or praise, which, as it were, itself raises songs; or it must be concrete, “everything glorious.”
Barnes is also helpful:
To the end that my glory may sing praise to thee - Margin, my "tongue," or my "soul." DeWette renders it, "my heart." The Aramaic Paraphrase: "that the honorable of the world may praise thee." The Septuagint and the Latin Vulgate: "my glory." The reference is, undoubtedly, to what the psalmist regarded as most glorious, honorable, exalted, in himself. There is no evidence that he referred to his "tongue" or his "heart" particularly, but the expression seems to be equivalent to "my highest powers" - all the powers and faculties of my nature. The "tongue" would indeed be the instrument of uttering praise, but still the reference is rather to the exalted powers of the soul than to the instrument. Let all that is capable of praise within me, all my powers, be employed in celebrating the goodness of God.