Interesting that this is the precise verse that Justin Martyr used in his “Dialogue With Trypho.” Only, he didn’t use it to try to show that Yahweh (or the LORD) consisted of two or more persons, but rather that the Father and the Son shared the name “Yahweh.”
Both Justin and Trypho throughout their dialogue had been referring to the Holy Spirit. Clearly Trypho didn’t mean another divine Person, since as a Jew, he believed that God was ONE divine Individual. The question is, "Did Justin mean another divine Individual? The following exchange suggests that he didn’t.
Justin asked Trypho this question:
“Do you think that any other one is said to be worthy of worship and called Lord and God in the Scriptures, except the Maker of all, and Messiah, who by so many Scriptures was proved to you to have become man?”
Trypho replied, “How can we admit this, when we have instituted so great an inquiry as to whether there is any other than the Father alone?”
If Justin had been a Trinitarian, this would have been a perfect opportunity to present the Holy Spirit as the Third Person of the Trinity. But he didn’t. Instead, he said:
“I must ask you this also, that I may know whether or not you are of a different opinion from that which you admitted some time ago.”
(Dialogue With Trypho, ch. LXVIII)