Vivaldi was in Rome for the carnival seasons of 1723 and 1724. While he was there he composed three operas for performance at the Capranica theatre – Ercole su’l Termodonte, Il Tigrane and Giustino. From the manuscript's paper we know that O qui caeli terraeque serenitas (RV631) must have been composed during one or other of Vivaldi's carnival Roman sojourns and based on this and his compositional activities it seems likely that he had in mind one or other of the leading ladies at the Capranica as the singer for this motet. I wish I knew who she was and a bit more about her because based on the evidence of this motet Vivaldi considered her to be a very good singer indeed.
It's another motet 'per ogni tempo' ('for all seasons') whose text is a prayer that the believer be delivered from earthly pleasures and that she may instead long for heavenly ones. Its central key is E flat major and Vivaldi uses 'sighing appoggiaturas in the first aria to depict the tempations of the world. The second aria uses what's called a lamento bass which is a descent by chromatic steps from tonic to dominant to depict the transitory nature of these mundane pleasures before a final exuberant Alleluia allows the singer to show us why she's a prima donna. Enjoy :-).