'Stedfast' in the Bible

'And now, O Jehovah, the word that Thou hast spoken concerning Thy servant, and concerning his house, let be stedfast unto the age, and do as Thou hast spoken;

and let it be stedfast, and Thy name is great unto the age, saying, Jehovah of Hosts, God of Israel, is God to Israel, and the house of Thy servant David is established before Thee;