Is there a grammatical basis for translating יְהוָ֑ה as the direct object of אָ֭הַבְתִּי in Psalm 116:1?

Question

English translations translate יְהוָ֑ה as the direct object of אָ֭הַבְתִּי in Psalm 116:1, but its position puts it as the subject of יִשְׁמַ֥ע in the following clause starting with כִּֽי. There seems to be a consensus among English translations to do this. Is there a grammatical basis for doing this or is it only contextual.

The Septuagint (LXX) does not do this:

Αλληλουια. Ἠγάπησα, ὅτι εἰσακούσεται κύριος τῆς φωνῆς τῆς δεήσεώς μου,... (Ps 114:1, LXX)

Nor, the Biblia Sacra Vulgata:

Dilexi quoniam exaudiet Dominus vocem orationis meae

It appears that a more accurate translation of

אָ֭הַבְתִּי‬ כִּֽי־יִשְׁמַ֥ע‬ יְהוָ֑ה אֶת־קֹ֝ולִ֗י תַּחֲנוּנָֽי would be "I love that the LORD hears my voice, my pleas..."

That is how the 1917 Jewish Publication Society of America translates:

I love that the LORD should hear my voice and my supplications. (JPS1917)

But the 1985 Jewish Publication Society of America translates:

  I love the LORD 
     for He hears my voice, my pleas; 
     

Answer 1

For what it is worth, I would translate Ps 116:1, 2 as:

I love because:

• YHWH has heard my voice and pleas
• He has inclined His ear to me

Therefore, as long as I live I will call [upon Him]

The only direct object marker is אֶת in V1 making "voice" the object of YHWH has heard.

Thus, Ps 116:1, 2 appears to be the predecessor idea behind 1 John 4:19 -

We love because He first loved us.

Answer 2

Here is the answer in the HALOT lexicon under כִּי

—6. the subject of the subordinate clause is made object of the principal sentence: Gn 1:4 that it was good (:: Albright ThZ 20:4: how good it was); the object is represented by הִיא etc. in the subordinate clause Gn 12:14; the same transposition of a time phrase: “I know after my death that”, for “I know that after my death”. Dt 31:29; כִּי separated from its governing verb Jb 20:4-5; the subject of the clause introduced with כּי becomes the genitive of the object in the governing clause Jb 22:12. -- Koehler, L., Baumgartner, W., Richardson, M. E. J., & Stamm, J. J. (1994–2000). In The Hebrew and Aramaic lexicon of the Old Testament (electronic ed., p. 471). E.J. Brill.