Laudator Temporis Acti

Cicero, On Divination 1.45.102 (tr. William Armistead Falconer):

Nor is it only to the voices of the gods that the Pythagoreans have paid regard but also to the utterances of men which they term 'omens.' Our ancestors, too, considered such 'omens' worthy of respect, and for that reason, before entering upon any business enterprise, used to say, 'May the issue be prosperous, propitious, lucky, and successful.' At public celebrations of religious rites they gave the command, 'Guard your tongues'; and in issuing the order for the Latin festival the customary injunction was, 'Let the people refrain from strife and quarrelling.'

neque solum deorum voces Pythagorei observitaverunt, sed etiam hominum, quae vocant omina. quae maiores nostri quia valere censebant, idcirco omnibus rebus agendis, 'quod bonum, faustum, felix fortunatumque esset' praefabantur; rebusque divinis, quae publice fierent, ut 'faverent linguis,' imperabatur; inque feriis imperandis, ut 'litibus et iurgiis se abstinerent.'

Cf. Livy 38.51.8 (speech of Scipio Africanus; emphasis added; tr. Evan T. Sage):

Therefore, since it is meet on this day to refrain from trials and quarrels, I shall proceed at once from here to the Capitoline to offer homage to Jupiter Optimus Maximus and Juno and Minerva and the other gods who preside over the Capitoline and the citadel, and I shall give thanks to them...

itaque, cum hodie litibus et iurgiis supersederi aequum sit, ego hinc extemplo in Capitolium ad Iovem optimum maximum Iunonemque et Minervam, ceterosque deos qui Capitolio atque arci praesident salutandos ibo, hisque gratias agam...