Mt 26:63-68, Mk 14:62-64, Lk 22:69-71, Acts 2:34-36

In the Old Testament David called Christ Lord. (Psalms 110:1)

Psalms 110:1 The Lord said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool.

When Jesus was captured by the Jews, he revealed that he was the Christ, the Son of God. (Matthew 26:63-68, Mark 14:62-64, Luke 22:69-71)

Matthew 26:63 But Jesus held his peace, And the high priest answered and said unto him, I adjure thee by the living God, that thou tell us whether thou be the Christ, the Son of God. 64 Jesus saith unto him, Thou hast said: nevertheless I say unto you, Hereafter shall ye see the Son of man sitting on the right hand of power, and coming in the clouds of heaven. 65 Then the high priest rent his clothes, saying, He hath spoken blasphemy; what further need have we of witnesses? behold, now ye have heard his blasphemy. 66 What think ye? They answered and said, He is guilty of death. 67 Then did they spit in his face, and buffeted him; and others smote him with the palms of their hands, 68 Saying, Prophesy unto us, thou Christ, Who is he that smote thee?

Mark 14:62 And Jesus said, I am: and ye shall see the Son of man sitting on the right hand of power, and coming in the clouds of heaven. 63 Then the high priest rent his clothes, and saith, What need we any further witnesses? 64 Ye have heard the blasphemy: what think ye? And they all condemned him to be guilty of death.

Luke 22:69 Hereafter shall the Son of man sit on the right hand of the power of God. 70 Then said they all, Art thou then the Son of God? And he said unto them, Ye say that I am. 71 And they said, What need we any further witness? for we ourselves have heard of his own mouth.

The Christ whom David called Lord in the Old Testament is Jesus. (Acts 2:34-36)

Acts 2:34 For David is not ascended into the heavens: but he saith himself, The Lord said unto my Lord, Sit thou on my right hand, 35 Until I make thy foes thy footstool. 36 Therefore let all the house of Israel know assuredly, that God hath made the same Jesus, whom ye have crucified, both Lord and Christ.