Laudator Temporis Acti

R.G.M. Nisbet, "On Housman's 'Juvenal'," Illinois Classical Studies 14.1/2 (Spring/Fall, 1989) 285-302 (at 288):

In his apparatus criticus Housman helpfully signalled his own conjectures with an asterisk; there are some 30 such asterisks. We may begin with 6.157 f. (on a precious ring):

                                            hunc dedit olim
barbarus incestae, dedit hunc Agrippa sorori.

For the inanely repeated dedit hunc, which disassociates incestae from sorori, Housman printed gestare (lost after -cestae), citing Virg. Aen. 12.211 patribusque dedit gestare Latinis. This was the kind of proposal that makes "the hair stand up on many uninstructed heads" (Manilius V, p. xxxiv), but it was characteristic of its author (posit the loss of an easily lost word followed by interpolation to restore the metre); Housman rightly insists that the plausibility of a conjecture does not depend on the number of letters changed. I have described gestare as the best emendation that has ever been made in Juvenal (JRS 52 [1962] 233), and this view has been endorsed by Professor Courtney in his commentary.

As translated by Susanna Morton Braund:

It was once given by the barbarian Agrippa to his incestuous sister to wear.

James Willis adopted Housman's conjecture in his Teubner edition; Wendell Clausen didn't in his Oxford Classical Text edition.

Cf. Herbert Jennings Rose, "Some Passages of Latin Poets," Harvard Studies in Classical Philology 47 (1936) 1-15 (at 14, footnotes omitted):

Housman would emend to incestae gestare, because it is absurd to suppose Juvenal, a first-rate rhetorician, splitting one act into two in this fashion. And indeed, if the lines mean simply "Herod Agrippa gave this ring to his sister and mistress," no one with any feeling for style will fail to agree. But I see no reason why they should be so understood. The emphatic hunc dedit . . . dedit hunc is sound and commendable if Juvenal is listing two generations of the diamond's pedigree, which is what I think he is doing. The barbarus is not Agrippa but Ptolemy, king of barbara Memphis; any Ptolemy who had married his sister would do, but the last of them has the advantage, for purposes of this piece of jewelry, of being the nominal husband of the best-known incesta of all to a Roman, Kleopatra VII. After her death, it would seem, Herod Agrippa got hold of it and gave it to Berenike, through whom it came to Rome, and so (from Titus?) into the market.

Courtney in his commentary doesn't mention Rose's defense of the parodosis.