Servius,  In Vergilii carmina commentarii - Aen. 8.721 (late fourth century A.D.):

DONA RECOGNOSCIT POPVLORVM aurum coronarium dicit, quod ‘triumphantibus' hodieque a victis gentibus datur. inponebant autem hoc imperatores propter concessam immunitatem. ideo ergo dixit ‘dona:' nam si hoc non esset, spolia diceret. APTATQVE SVPERBIS POSTIBVS porticum enim Augustus fecerat in qua simulacra omnium gentium conlocaverat: qua porticus appellabatur ‘ad nationes.'

HE REVIEWS THE GIFTS OF THE PEOPLES Virgil speaks about the golden wreath, because ‘for those triumphing' even now it is given from defeated peoples. However imperatores imposed this because of the lawful immunity. Therefore on that account he said, "gifts:" for if this were not [so], he might have said the spoils of war. AND HE HANGS [THE GIFTS] UPON THE UPPER PART OF THE DOOR-POSTS for Augustus had made a porticus in which he assembled statues of all the nations, from which this porticus was named ‘for the nations.'  (U. K. Vestal, trans.)