'Never Fail' in the Bible

and so that the Lord will carry out His promise that He made to me: ‘If your sons are careful to walk faithfully before Me with their whole mind and heart, you will never fail to have a man on the throne of Israel.’

Therefore, Lord God of Israel,keep what You promisedto Your servant, my father David:You will never fail to have a manto sit before Me on the throne of Israel,if only your sons guard their walk before Meas you have walked before Me.

I will establish your royal throne over Israel forever, as I promised your father David: You will never fail to have a man on the throne of Israel.