Proud purple kings shall kneel before thy throne,
Mix’d with the poor, their pomp, their glory gone:
All vain distinctions levelled by the grave,
Thy righteous sentence shall condemn or save.

[Sub tua purpurei venient vestigia reges
deposito luxu turba cum paupere mixti
(omnia mors aequat); tu damnatura nocentes,
tu requiem latura piis.]

claudius claudianus
Claudian (c. AD 370-404) Greco-Latin poet [Claudius Claudianus; Κλαυδιανός]
The Rape of Prosperine [De Raptu Proserpinæ], Book 2, I. 300 (c. AD 396) [tr. Howard (1854)]
    (Source)

Pluto reassuring Proserpine that being Queen of the Underworld has its benefits.

Source of the phrase Omnia mors æquat, "Death levels all things" or "Death makes all equal."

(Source (Latin)), Alternate translations:

The rich-clad purple kings shall humbly fall
Before thy throne (mixt with the poore) for all
Death equals; thou the guilty and unjust
Shalt judge, with them, the Innocente and Just.
Those shall bewaile their crimes, these shall be blest
By thee, and sent into eternal rest.
[tr. Diggs (1617)]

Before thy lofty Throne, the haughty Pride
Of mighty Kings, their Purple laid aside
And Pageantry of State, shall lowly fall,
Mix'd with the poorer Rout, for Death will equal all.
In Judgement thou shalt sit, with Pow'r supreme,
To crown the Pious and the Bad condemn.
[tr. Hughes (1723)]

Monarchs shall appear
Before thee, spoil'd of regal ornament,
And undistinguish'd from the vulgar crowd:
Death renders all men equal. Thou shalt judge
The guilty; and thy hand shall give the meed
To virtue.
[tr. Strutt (1814), l. 369ff]

To thy feet shall come purple-clothed kings, stripped of their pomp, and mingling with the unmoneyed throng; for death renders all equal. Thou shalt give doom to the guilty and rest to the virtuous.
[tr. Platnauer (Loeb) (1922)]