The hair she swears is hers Fabulla bought.
So, Paulus, is that perjury or not?

[Iurat capillos esse, quos emit, suos
Fabulla: numquid, Paule, peierat?]

Martial (AD c.39-c.103) Spanish Roman poet, satirist, epigrammatist [Marcus Valerius Martialis]

Epigrams [Epigrammata], Book 6, epigram 12 (6.12) (AD 91) [tr. McLean (2014)]
    (Source)

Perhaps a reference back to Paulus doing something similar with poetry (ep. 2.10). (Source (Latin)). Alternate translations:

You see the goodly hayre that Galla weares,
'Tis certain her own hair, who would have thought it?
She sweares it is her owne: and true she sweares:
For hard by Temple-barre last day she bought it.
[tr. Harington (fl. c. 1600), Ep. 162 - Epigrams Book 2 #66 "Of Galla's goodly Periwigge"]

The golden hair that Galla wears
Is hers: who would have thought it?
She swears 'tis hers, and true she swears,
For I know where she bought it.
[tr. Harington (fl. c. 1600), as paraphrased in Bohn, possibly from Anon. below.]

Fabulla sweares her haire (which at a rate
She bought) is hers. Is she forsworne in that?
[tr. May (1629)]

Shee sweares tis her owne hayre. Who would have thought it?
Shee's nott forsworne though: I know where shee bought it.
[tr. Anon. - British Library MS Add. 27343 (17th C)]

Locks Fabby purchas'd, and her own she swore.
Who would not, Paul, the perjury deplore?
[tr. Elphinston (1782), Book 12, ep. 163]

Fabulla swears that the hair which she has bought is her own. Does she perjure herself, Paulus?
[tr. Bohn's Classical (1859)]

Fabulla swears that the hair she buys is hers.
Does she therefore swear falsely, Paulus?
[tr. Ker (1919)]

Those purchased tresses which her head adorn
Fabulla swears are hers -- is she forsworn?
[tr. Pott & Wright (1921), "By Right of Purchase"]

That plush hair Fabulla wears?
It's hers, Fabulla swears.
I've no reason to deny it:
I saw Fabulla buy it.
[tr. Matthews (1992)]

Fabulla swears that the hair she buys is her own. Is that perjury, Paulus?
[tr. Shackleton Bailey (1993)]

Swears Fabby of her hair so fine,
"I purchased it, so, yes, it's mine."
[tr. Ericsson (1995)]

The coif she wears she claims she grew.
Does that seem splitting hairs to you?
[tr. Wills (2007)]

She swears the hair she bought is her own.
Is she lying? No.
[tr. Kennelly (2008), "No Lie"]

Fabulla swears that hair is hers -- the hair she bought; tell me, Paulus, is she lying?
[tr. Nisbet (2015)]