Psalms 118:25

Save now, I beseech thee, O Lord
Or, "we beseech thee"; for they are the words of the people, wishing all health and happiness to their king; and it is as if they had said, "vivat rex", that is, "let the king live", or, "God save the King": and no doubt these words were used by the people, when all the tribes united and made David king over all Israel, and when he became the head of the corner; which was attended with the shouts and acclamations of the people, expressing themselves after this manner, And certain it is that these words were used by the followers of Christ, and applied to him, when he made his public entry into Jerusalem, crying, "hosanna" to the son of David. The word "hosanna" is the same with "save now"; and is compounded of the two words in the text thus translated, ( Matthew 21:9 ) ;

O Lord, I beseech thee, send now prosperity;
to our King: give him success in all his undertakings, and victory over all his enemies; may the pleasure of the Lord prosper in his hands; may his Gospel run and be glorified, and be spread all over the world, and multitudes bow to the sceptre of his kingdom; may his kingdom be enlarged, and his dominion be from sea to sea; and may this spiritual building rise, and be brought to perfection, of which he is the foundation and chief corner stone. The allusion may be to the shouts usually made at the laying of the foundation or corner stone of any considerable edifice, and at the bringing in the head stone of it; see ( Ezra 3:11 ) ( Zechariah 4:7 ) .