In the Sermon on the Mount, Jesus uses κυριος twice to refer to himself:
Not
every one that saith unto me, Lord, Lord (κυριε κυριε), shall enter into the kingdom of
heaven, but he that doeth the will of my Father which is in heaven. Many will
say to me in that day, Lord, Lord (κυριε κυριε), have we not prophesied in thy
name? and in thy name have cast out devils? and in thy name done many wonderful
works? (Matt 7:21-22)
When one examples the double use
of κυριος in the LXX, one will see that this is used of YHWH,
showing that, in Jesus’ self-designation of himself, we have potentially a very
high Christology in the Gospel of Matthew. Consider the following representative
examples from the LXX (using the NETS translation):
"O
Lord, Lord (HEB: אדני יהוה), you have begun to show your attendant your
strength and your power and your strong hand and your high arm. For what god is
there in the sky or on the earth who will do as you have done, and according to
your strength?" (Deut 3:24)
And
I prayed to God and said, "O Lord, Lord (HEB: אדני יהוה), king of the
gods, do not utterly destroy your people and your possession whom you redeemed
by your great strength, whom you brought out of the land of Egypt with your
great strength and with your strong hand and your high arm. (Deut 9:26)
For
this is what the Lord (LXX reads κυριος κυριος; HEB: אדני יהוה) says: The city
out of which a thousand were going forth, there shall be left a hundred, and
out of which a hundred were going forth, there shall be left then to the house
of Israel. (Amos 5:3)
And
it will be, if they finish to devour the grass of the land-and I said, "O
Lord, O Lord (LXX: κυριος κυριος; HEB: אדני יהוה), be gracious. Who
will raise up Iakob, because he is very small? (Amos 7:2)
And
I said, O Lord, O Lord (LXX: κυριος κυριος; Heb: אדני יהוה), do cease! Who
will raise up Iakob, because he is very small? (Amos 7:5)
And
you will say, 'O Lord, O Lord (LXX: κυριε κυριε; HEB: יהוה), it was you who spoke
against this place to destroy it utterly and so that neither human nor animal
inhabitants in it, because it shall be an annihilation forever.' (Jer 28:62
[English: 51:62])
And
you shall say to them, This is what the Lord (LXX: κυριος κυριος; HEB: אדני יהוה)
says: Behold, I am taking the whole house of Israel from the midst of the
nations, there where they went, and I will gather them from all those around
them and bring them into the land of Israel. (Ezek 37:21)