John Gill's Exposition of the Whole Bible
Proverbs 30:15
The horse leech hath two daughters, [crying], Give, give,.... Or "the blood sucker" l; so it began to be called in the times of Pliny m, to which the last generation of men may well be compared; blood thirsty creatures, that never have enough, and are not satisfied with the flesh of men, nor with their blood; and such particularly the Papists are: and not only this generation of men, but there are three or four things besides, which resemble the horse leech for its insatiableness; for the horse leech has not two daughters only, but more. Some, by her two daughters, understand the two forks of its tongue, which some naturalists say it has; though later ones, and more diligent inquirers into those things, find it has not; but either with its three teeth, or by the compression of its mouth on all sides, sucks the blood, and will not let go until it is filled with it n: others have proposed the two sorts of leeches as its daughters, the sea leech, and that which is found in fenny and marshy places. But it is best, by its daughters, to understand such that resemble it, and are like unto it; as those that are of like nature and quality, and do the same things as others, are called their children; see Matthew 23:31 1 John 3:10; and so the number of its daughters, which are always craving and asking for more, and are never satisfied, are not only two, but more, as follows;
there are three [things]; or, "[yea], there are three [things]"
[that] are never satiated: [yea], four [things] say not, [It is] enough; not two only, but three, and even four, that are quite insatiable and are as follow. The Syriac version renders the whole thus,
"the horse leech hath three beloved daughters; three, "I say", they are, which are not satisfied; and the fourth says not, It is enough.''
Some, as Abendana observes, interpret it of hell, by a transposition of the letters; because everyone that perverts his ways descends thither. Bochart o interprets it of fate, and so Noldius p: and Schultens renders the word, the most monstrous of evils; it signifying in the Arabic language, as he observes, anything monstrous and dreadful; such as wood demons, serpents, and dragons, which devour men and beasts. Suidas q, by the "horse leech", understands sin, whose daughters are fornication, envy, and idolatry, which are never satisfied by evil actions, and the fourth is evil concupiscence.
l לעלוקה "sanguisugae", V. L. Pagninus, Tigurine version. Mercerus, Gejerus. m Nat. Hist. l. 8. c. 10. n "Non missura cutem nisi plena cruoris hirudo", Horat. de Arte Poet. fine. o Hierozoic. par. 2. l. 5. c. 19. col. 801. p Concord. Ebr. Par. p. 467. No. 1425. q In voce βδελλα.