Direct biblical statement
Luke 1:32–33
His kingdom shall have no end
32 He shall be great and shall be called the Son of the Most High. And the Lord God shall give unto him the throne of David his father: and he shall reign in the house of Jacob for ever.
33 And of his kingdom there shall be no end.
Douay–Rheims · Challoner revision · Luke 1:32–33
Why this matters
Mary will bear Jesus, the Son of the Most High, who receives David’s throne. The promise concerns the identity and enduring reign of her Son; Mary’s royal significance is understood in relation to him.