See Book I, line 726 of Virgil's epic poem, the Aeneid.
The line quoted by Eliot has been translated as:
burning lamps hang from the gold-panelled ceiling,
and torches dispel the night with their flames.
This is from Virgil's description of a banquet given by Dido, Queen of Carthage for Aeneas, with whom the gods made her fall in love. Just as Queen Cleopatra commits suicide due to her involvement with Antony, Dido's passion for Aeneas also leads to her suicide.
In other poetic translations of the Aeneid available at this web site Virgil's lines are given as:
From gilded roofs depending lamps display
Nocturnal beams, that emulate the day.
from the gilded vault
far-blazing cressets swing, or torches bright
drive the dark night away.
It is recommended that novices to The Waste Land skip the context reading of Eliot's quoted line for the Aeneid for some later time. This commentator's belief is that the noted line is not very important by itself but is a way of alluding to the relationship between Aeneas and Dido. This site has a section from Bulfinch's Mythology giving a synopsis of Aeneas and Dido from the plot of the Aeneid. This synopsis is recommended for reading now. Note though that it goes lightly over a few points that this commentator would emphasize (and may emphasize in a future edition.)
Now, with that advice given, you can view, if you wish, a section of Book I of the Aeneid and some poetic translations.
The Exploring The Waste Land site also has an old, but public domain, encyclopedia entry for Aeneas.