Laudator Temporis Acti

Aristophanes, Wasps 392 (in a prayer to the hero Lycus, tr. Alan H. Sommerstein):

You are the only Hero who has chosen to take his seat near a crying man.

κἀβουλήθης μόνος ἡρώων παρὰ τὸν κλάοντα καθῆσθαι.

Douglas M. MacDowell ad loc.:

μόνος is common in prayers; a god is praised especially for those qualities or functions which no other god has. Cf. Peace 590, Birds 1546, Th. 1141, Ek. 12.

Here the quality peculiar to Lycus is his willingness to put up with whining. Sommerstein ad loc.:

In general it was improper to approach a god or hero with weeping or wailing; Apollo was particularly averse to manifestations of grief in his presence (cf. Aesch. Ag. 1072-9; Eur. Supp. 971-6), but other gods too might be held to object to them.

Examples of μόνος or solus in prayers are ubiquitous. Two Latin examples come immediately to mind.

The first is the prayer to Venus at the beginning of Lucretius' De Rerum Natura (1.30-31, tr. H.A.J. Munro):

For thou alone canst bless mankind with calm peace.

Nam tu sola potes tranquilla pace iuvare / mortalis.

The second is the last part of the Gloria in the Mass:

For thou alone art holy. Thou alone art the Lord. Thou alone art most high, Jesus Christ. With the Holy Ghost, in the glory of God the Father. Amen.

Quoniam tu solus Sanctus. Tu solus Dominus. Tu solus Altissimus, Jesu Christe. Cum Sancto Spiritu, in gloria Dei Patris. Amen.