Sorry @TheologyNerd
When the covenant with Israel is established in the Old Testament, who is speaking and acting according to the text itself?
At Sinai, the covenant is explicitly established by YHWH. Exodus 24:8 states:
Exo 24:8 And Moshe took the remaining dahm, and sprinkled it on HaAm, and said, Hinei dahm habrit, which Hashem hath cut with you concerning all these words.
The covenant is said to be made by “the LORD” which in the Hebrew text is YHWH. The text does not distinguish Father, Son, and Spirit at that point. It simply identifies the covenant maker as YHWH, the God of Israel.
Deuteronomy 5:2 says the same:
Deu 5:2 Hashem Eloheinu made a Brit with us in Chorev.
Again, it is YHWH.
Now move to the New Testament. The Father is clearly identified as God. For example, 1 Corinthians 8:6 says:
1Co 8:6 Yet in fact for us we have da’as that there is ADONOI ECHAD ("L-rd is One " DEVARIM 6:4), Hashem AV ECHAD L’CHULLANU ("One Father of us all” MALACHI 2:10), from whom are all things, and we exist for Hashem, and there is Adon Echad [MALACHI 3:1], Moshiach Yehoshua [ZECHARYAH 3:8; 6:11-12], through whom are all things and we through him.
The Son is also identified as fully divine. John 1:1 says:
Bereshis (in the Beginning) was the Dvar Hashem [YESHAYAH 55:11; BERESHIS 1:1], and the Dvar Hashem was agav (along with) Hashem [MISHLE 8:30; 30:4], and the Dvar Hashem was nothing less, by nature, than Elohim! [Psa 56:11(10); Yn 17:5; Rev. 19:13]
And Hebrews 1:8 applies divine kingship language to the Son:
Heb 1:8 And Hashem says to HaBen, KIS’AHCHA ELOHIM OLAM VAED SHEVET MISHOR SHEVET MALKHUTECHA (“Your throne, O G-d, will endure for ever and ever, and the scepter of justice is the scepter of your kingdom” --TEHILLIM 45:7).
Heb 1:9 AHAVTA TZEDEK VATISNA RE’SHA, AL KEN MESHAKHACHA ELOHIM, ELOHECHA SHEMEN SASSON MECHAVERECHA (“You loved righteousness and hated lawlessness; on account of this G-d, your G-d, anointed you with the oil of gladness more than your companions”–TEHILLIM 45:8).
So biblically, YHWH is the covenant maker. The New Testament reveals that the Father is God, the Son is God, and the Spirit is God, yet there is one God.
What does the Bible explicitly say about covenant mediation? Hebrews 8:6 says of Christ:
And Hebrews 9:15:
So the Old Covenant is said to be made by YHWH. The New Covenant is said to be mediated by Christ through His death and resurrection.
The Bible does not contain a verse that says, “The Son established the Sinai covenant,” nor does it say, “Only the Father established it.” It says YHWH made it. Then the New Testament reveals that Jesus shares in the divine identity of YHWH.
So strictly from the text:
• The covenant at Sinai was established by YHWH.
• The Father is called God.
• The Son is called God.
• Christ mediates the New Covenant through His blood.
Deuteronomy 5:2 reads:
יְהוָה אֱלֹהֵינוּ כָּרַת עִמָּנוּ בְּרִית בְּחֹרֵב
The verb כָּרַת (kārat) is Qal perfect 3rd masculine singular. The subject is יְהוָה (YHWH), a singular proper noun. The perfect form presents the action as completed. Grammatically, the one performing the action of covenant cutting is singular. There is no plural verb and no compound subject. The morphology identifies one grammatical actor: YHWH.
Exodus 24:8 contains:
אֲשֶׁר כָּרַת יְהוָה עִמָּכֶם
Again, כָּרַת is Qal perfect 3ms. The subject is explicitly יְהוָה. The agreement is singular masculine. Hebrew grammar here is unambiguous. A singular subject performs a singular completed action.
Exodus 19:5 includes:
וּשְׁמַרְתֶּם אֶת־בְּרִיתִי
בְּרִיתִי is בְּרִית (covenant) with 1st person singular pronominal suffix, “my covenant.” The suffix ִי marks possession by a singular speaker. That speaker in context is יְהוָה. The covenant is grammatically owned by a singular “I.”
The divine name יְהוָה itself is morphologically singular. Though אֱלֹהִים can be morphologically plural, when referring to the God of Israel it takes singular verbs and adjectives. In Deuteronomy 5:2, the verb is singular, confirming singular grammatical agency.
So strictly at the morphological level:
• The covenant verb כָּרַת is singular.
• The subject יְהוָה is singular.
• The possessive suffix “my covenant” is singular.
• There is no grammatical plurality in the covenant-making action.
The text presents one grammatical actor: YHWH.
Now, the New Testament later identifies the Son as sharing the divine identity, but that is theological synthesis drawn from later revelation. Morphologically, in the Sinai covenant texts themselves, the covenant is established by a singular subject, יְהוָה, acting in the Qal perfect 3ms.
Grammar does not speculate. It simply shows one covenant maker in the text: YHWH.
J.