[As] a jewel of gold in a swine's snout
The allusion seems to be to the ringing of swine, to prevent their rooting up the earth; which is usually done by putting an iron ring into their snout; which is much more proper and suitable than a gold ring, or a jewel set in gold, which is very unbecoming such a creature; and is soon had to the dunghill, or to some miry place, and there defiled; [so is] a fair woman which is without discretion;
or, "has departed from taste" F25; from a taste of virtue and honour; lost all sense of modesty and chastity; forsaken her husband, and given up herself to the embraces of others. As her beauty is fitly expressed by a "jewel of gold", which is valuable and desirable, and, rightly placed and used, is ornamental; so she is properly represented by a swine, wallowing in the impurities of lust; to which her beauty was the snare, and whereby it is quickly sullied and lost. Jarchi applies this to a disciple of a wise man, or a scholar that departs from the good way, or from the law; which he explains by taste or sense: but it may be better applied to the scarlet whore, or apostate church of Rome; which has departed from Christ, once her professed husband; from the doctrines of the Gospel, and the ordinances of it; from all taste and savour of true religion; and even from common sense and right reason, as in the affair of transubstantiation, and other things; and may be fitly compared to a swine with a jewel of gold in its snout, being "decked with gold, and precious stones, and pearls"; and yet "drunk with the blood of the saints", and "martyrs of Jesus"; and wallowing in all the faith of fornication, of idolatry, and superstition; as well as in all manner of other sins and iniquities, ( Revelation 17:4-6 ) .
The Brenton translation of the Septuagint is in the public domain.