Were full of wrath - Were greatly enraged - probably at the prospect of losing their gains.
Great is Diana - The term "great" was often applied by the Greeks to Diana. Thus, in Xenophon (Ephes. i.), he says, "I adjure you by your own goddess, the great (τὴν μεγάλην tēn megalēn) Diana of the Ephesians." The design of this clamor was doubtless to produce a persecution against Paul, and thus to secure a continuance of their employment. Often, when people have no arguments, they raise a clamor; when their employments are in danger of being ruined, they are filled with rage. We may learn, also, that when people's pecuniary interests are affected, they often show great zeal for religion, and expect by clamor in behalf of some doctrine to maintain their own interest, and to secure their own gains.

And when they heard these sayings,.... Both the masters and the workmen;
they were full of wrath; against Paul and his doctrine:
and cried out, saying, great is Diana of the Ephesians; this goddess is frequently called in Heathen writers, Diana of the Ephesians, or the Ephesian Diana, because of her famous temple at Ephesus; and to distinguish her from all other Dianas: Pausanias makes mention of sixty Dianas at least, and yet seems not to have taken notice of them all; all of them had different epithets, by which they were distinguished from one another; the images were in different shapes, and they were worshipped with different rites: what seems most of all to distinguish the Ephesian Diana from others, is her having many paps; hence she is called, "multi mammia"; so Minutius Felix observes (t), that Diana is sometimes girt about on high as an huntress, and the Ephesian Diana is "mammis multis & uberibus extructa"; Just as the Isis of the Egyptians, which, Macrobius (u) says, signifies the earth; hence the whole body of the deity is covered with paps, because the whole universe is nourished by it: the priest of Diana of the Ephesians was an eunuch, and was obliged to abstain from all company; neither bathed, nor ate, nor drank with others, nor might he enter into the house of a private person; there was a feast kept every year in honour of her, at which young men in the flower of their age, and virgins well dressed, used to go to the temple in great pomp, keep the feast, and marry with each other. The temple was a sort of an asylum, as Heathen temples commonly were; and it had this particular privilege, that those that fled to it were freed from servitude (w). This goddess is called "great", agreeably to her name, for, "Diana", signifies "great" and venerable; because of her birth, being the daughter of Jupiter; and because of her great service, she was supposed to be of in assisting at births; and because of her magnificent temple and worship; and because she was worshipped by great persons: and here greatness is ascribed unto her, and a loud cry made of it, to animate one another, to gather a mob together, and to incense them and stir them up against the apostle and his companion: in the Arabic version, instead of Diana, it is Venus, both here and elsewhere, but wrongly.
(t) In Octavia, p. 22. (u) Saturnal. l. 1. c. 20. (w) Pausauias in Arcadicis, sive, l. 8. p. 476. Alex. Genial. Dier. l. 3. c. 20. & l. 6. c. 2. & c. 12.

Great is Diana of the Ephesians--the civic cry of a populace so proud of their temple that they refused to inscribe on it the name of Alexander the Great, though he offered them the whole spoil of his Eastern campaign if they would do it [STRABO in HOWSON].