Revelation 18:3

For all nations have drunk of the wine of the wrath of her
fornication
That is, all the nations of the Roman empire, the European nations, otherwise the Pagan and Mahometan nations have not; but these have, being made to drink by her, and made drunk therewith, that is, with her idolatries; (See Gill on Revelation 14:8).

And the kings of the earth have committed fornication with her;
joined with her in her idolatrous worship and practices, and encouraged the same, and obliged their subjects to them in their dominions; (See Gill on Revelation 17:2).

And the merchants of the earth are waxed rich through the abundance
of her delicacies;
or "luxury"; which is not to be understood in a literal sense; though it is true that many merchants, in all ages, have enriched themselves by sending their commodities to Rome, where, through the vast consumption and luxuriousness of the place, they have bore a good price; but this is to be interpreted of spiritual merchants; these are such who do not merchandise by sea, but are land merchants, the merchants of the earth, and are said to be the great men of the earth, ( Revelation 18:23 ) such as are equal to princes, lords, and nobles; such are the cardinals, archbishops, and bishops; though the inferior clergy of the Romish church, who are under these, may be included: to which may be added, that one part of their wares is said to be the souls of men, ( Revelation 18:13 ) which plainly shows what sort of merchants these are; they are such who make merchandise of men, and pretend to sell them heaven, and the salvation of their souls; these are they that deal in pardons and indulgences, which they sell to ignorant people, and for a sum of money say Mass to fetch souls out of purgatory: all things have been saleable at Rome, crucifixes, priests, altars, temples, prayers, heaven, Christ, yea, God himself, as the poet Mantuan expresses it; and because of these idolatries, and wicked practices, Rome will be at last destroyed.