Hebrews 1:8

1:8 but of the Son he says,

“Your throne, O God, is forever and ever,

and a righteous scepter is the scepter of your kingdom.

Hebrews 7:21

7:21 but Jesus did so with a sworn affirmation by the one who said to him, “The Lord has sworn and will not change his mind, ‘You are a priest forever’” –

Hebrews 7:28

7:28 For the law appoints as high priests men subject to weakness, but the word of solemn affirmation that came after the law appoints a son made perfect forever.