Psalm 89:37
35 Once and for all I have vowed by my own holiness, I will never deceive David. 36 His dynasty will last forever. His throne will endure before me, like the sun; 37 it will remain stable, like the moon. His throne will endure like the skies.” (Selah) 38 But you have spurned and rejected him; you are angry with your chosen king. 39 You have repudiated your covenant with your servant; you have thrown his crown to the ground.
John 12:34
32 And I, when I am lifted up from the earth, will draw all people to myself.” 33 (Now he said this to indicate clearly what kind of death he was going to die.) 34 Then the crowd responded, “We have heard from the law that the Christ will remain forever. How can you say, ‘The Son of Man must be lifted up’? Who is this Son of Man?” 35 Jesus replied, “The light is with you for a little while longer. Walk while you have the light, so that the darkness may not overtake you. The one who walks in the darkness does not know where he is going. 36 While you have the light, believe in the light, so that you may become sons of light.” When Jesus had said these things, he went away and hid himself from them.
Notes and References
"... The crowd voices a difficulty which the representatives of Jesus were to face from Good Friday onward. The “Law” (= the Old Testament, supremely represented by the Law) says that the Messiah remains “for ever.” The scripture passage is likely to be Psalm 89:37, “His seed shall remain for ever, his throne as long as the sun before me” . For most Jews the perpetuity of the kingdom of God included the continuance of the Messiah (contrary to the later view represented in 4 Ezra 7:28—29, that the messianic kingdom will be temporary and will end with the death of the Messiah and all flesh with him). The crowd therefore asks, “How can the Son of Man-Messiah be ‘lifted up,’ and so removed from the earthly scene by death?” Their further query, “Who is this Son of Man?” means, “What sort of a Son of Man is this, of whom such an unheard of fate is spoken?” ..."
Beasley-Murray, George R. Word Biblical Commentary: John (p. 215) Word Books, 1987