For in ora, compare Catullus XL 5 'an ut peruenias in ora uulgi [sc hoc facis]?', Hor Ep I iii 9 '... Titius, Romana breui uenturus in ora', Prop III ix 32 (to Maecenas) 'et uenies tu quoque in ora uirum', Tr V vii 29-30 'non tamen ingratum est quodcumque obliuia nostri / impedit et profugi nomen in ora refert', and Livy II 36 3. The only instance I have found of the expression being used of a thing rather than a person other than this passage is also from Ovid: 'illud opus ... nunc incorrectum populi peruenit in ora, / in populi quicquam si tamen ore mei est' (Tr III xiv 21-24). Neither passage would have seemed strange to the Romans, given the close identification between poet and work: compare Ennius' famous 'uolito uiuo' per ora uirum' and Met XV 878 'ore legar populi'.
19. QVAE PIETAS. 'This demonstration of loyalty'.
20. SACRAE ... DOMVS. Augustus' house called 'magni ... Iouis ... domum' at Tr III i 38; compare as well EP III i 135 'domus Augusti, Capitoli more colenda'.
20. MITIOR IRA. Compare EP III iii 83 'pone metus igitur: mitescet Caesaris ira'.
21. LIQVIDO POSSVM IVRARE. 'I can swear unambiguously'. The only other instance of this sense in verse apparently III iii 49-50 'scis tamen et liquido iuratus dicere possis / non me legitimos sollicitasse toros'. From prose compare Cic II Verr IV 124 'confirmare hoc liquido, iudices, possum, ualuas magnificentiores ... nullas umquam ullo in templo fuisse', II Verr III 136, Fam XI 27 7 'alia sunt quae liquido negare soleam', and Sen Ben VII 9 5.
22. NON DVBIA ... NOTA. The phrase logically belongs with the preceding line: on the firm evidence of Brutus' past behaviour (described in 23-42), Ovid can confidently state that Brutus prays for his restoration. Non dubia by litotes for certa (for which see Her XX 207 'te ... nimium miror, nota certa furoris'); nota 'tangible sign, evidence' similarly used at Met I 761 (generis). FIDE (LTM2ulF2ul) is an obvious gloss for nota.
23. VERVM ... AMOREM. 'Sincere love' (Wheeler); compare Met V 61 'ueri non dissimulator amoris' and Tr IV iv 71 'et comes exemplum ueri Phoceus amoris'.
25. TVAS ... LACRIMAS NOSTRASQVE. The tears of Ovid's friends at his departure described at Tr III iv 39-40, EP I ix 17-18, and EP II xi 9-10 (to Rufus) 'grande uoco lacrimas meritum quibus ora rigabas, / cum mea concreto sicca dolore forent'.
26. PASSVROS POENAM CREDERET ESSE DVOS. Compare Tr V iv 37-38 (Ovid's letter speaking) 'quamuis attonitus, sensit tamen omnia, nec te / se minus aduersis indoluisse suis'.
27. LENEM TE MISERIS GENVIT NATURA. Compare Cic Tusc II 11 'te natura excelsum quendam uidelicet et altum et humana despicientem genuit' and Ennius Ann 112 Vahlen3 (of Romulus) 'qualem te patriae custodem di genuerunt'.