According to Unitarians, to whom does the word הָאָדוֹן refer in Mal. 3:1?

Regarding the word אֲדֹנִי (*adoni*) in Psa. 110:1 (actually prefixed with -ל, i.e. לַאדֹנִי), translated as “my lord,” a self-professed Unitarian website states,1 >Trinitarian commentators frequently argue that “my Lord” in this verse is the Hebrew word adonai, another name for God, and is therefore proof of the divinity of the Messiah. But not only is this not a valid argument, this verse is actually one of the great proofs of the complete humanity of the promised Messiah. The Hebrew word translated “my lord” is adoni (pronounced “Adon nee” [1] ) in the standard Hebrew texts. **This word is always used in Scripture to describe human masters and lords, but never God**. (*emphasis mine*) Now, the Hebrew word אֲדֹנִי is simply the lemma or base form אָדוֹן2 with a 1st person singular pronominal suffix appended (i.e., “my”). The question, then, should **not** be limited to whether אֲדֹנִי is ever used in reference to Yahveh (God), but rather, whether אָדוֹן and **any** of its suffixed forms (including אֲדֹנִי) are ever used in reference to Yahveh. After all, couldn’t “lord,” “my lord,” “his lord,” “our lord,” and “their lord” all refer to the same “lord”? - The lord said to Abraham and Sarah,... - Abraham said to his lord,... - Sarah said to her lord,... - Sarah and Abraham spoke to their lord,... - Sarah and Abraham said, “Our lord...” - Abraham said, “My lord...” In this context, the “lord” is the same person, regardless of the pronominal suffix. Hence, limiting the discussion to “my lord” is both arbitrary and disingenuous. I encountered the word הָאָדוֹן in Mal. 3:1 . This is simply אָדוֹן prefixed with the definite article הָ, meaning “the lord” (i.e., “the master”). The Hebrew text of Mal. 3:1 states, >הִנְנִ֤י שֹׁלֵחַ֙ מַלְאָכִ֔י וּפִנָּה־דֶ֖רֶךְ לְפָנָ֑י וּפִתְאֹם֩ יָבֹ֨וא אֶל־הֵיכָלֹ֜ו הָאָדֹ֣ון אֲשֶׁר־אַתֶּ֣ם מְבַקְשִׁ֗ים וּמַלְאַ֨ךְ הַבְּרִ֜ית אֲשֶׁר־אַתֶּ֤ם חֲפֵצִים֙ הִנֵּה־בָ֔א אָמַ֖ר יְהוָ֥ה צְבָאֹֽות׃ which is translated into English as, >Behold, I am sending My messenger, and he shall prepare a way before Me, and the lord whom you are seeking shall suddenly come to His temple, and/even the messenger of the covenant whom you delight in. Behold, he comes," said Yahveh of hosts. We note a couple of things during exegesis of Mal. 3:1 : 1. Yahveh of hosts is the speaker. - “I am sending My messenger” evidently refers to Yahveh sending His messenger (cp. 2 Chr. 36:15-16 ; Isa. 42:19 ). - Thus, first-person pronouns refer to Yahveh, such as “**My** messenger,” “before **Me**,” etc. However, note the acute analysis of Carl Friedrich Keil in his commentary on Mal. 3:1 : >“The Lord” ((hâ'âdōn)) is God; this is evident both from the fact that He comes to His temple, i.e., the temple of Jehovah, and also from the relative clause “whom ye seek,” which points back to the question, “Where is the God of judgment?” (Malachi 2:17 ). **The question**: How do Unitarians refute the assertion that הָאָדוֹן (*ha-adon*) refers to Yahveh (God) in Mal. 3:1 ? **Footnotes** 1 URL: http://www.biblicalunitarian.com/verses/psalm-110-1 2 meaning “master,” “lord,” “sir” **References** Keil, Carl Friedrich. *Commentary on the Old Testament. * 1900. Reprint. Trans. Martin, James. Vol. 10. Grand Rapids: Eerdmans, 1988. (458)