Save now, I beseech thee, O Lord ... - The word save here seems to be used in the general sense of imploring the divine interposition and mercy. It is a part of the word which in the New Testament is rendered “Hosanna” - save now Matthew 21:9 - and is the language which the multitudes employed when they followed the Saviour as he went from the Mount of Olives to Jerusalem. The language which they used on that occasion was borrowed from this psalm, and was eminently appropriate to the occasion - “Hosanna - blessed be he that cometh in the name of the Lord;” but the fact that it was thus employed does not prove that the psalm had original reference to the Messiah. The language was not improbably used on high festivals, and would be naturally employed when the Messiah came.
Send now prosperity - Give success; be favorable. God had interposed, and now the prayer is, that there might be continued and uninterrupted prosperity; that as the tide had begun to turn in the psalmist’s favor, it might recede no more; that the calamities and woes which he had experienced might not be repeated. This was omitted in the acclamations of the multitude that attended the Saviour Matthew 21:9; but it is eminently an appropriate prayer to be used in connection with his coming - since his coming, whether to the world, to an individual, to a church, or to a community, brings the highest kind of “prosperity” in its train.