Leviticus 18:14

Lev 18:14 Thou shalt not uncover the nakedness of thy father’s brother, thou shalt not approach to his wife: she [is] thine aunt.

Ver. 14. Of thy father’s brother.] The nakedness of whose wife is called his nakedness, because man and wife are one flesh. {Mat 19:6} {See Trapp on "Mat 19:6"}

John Trapp, A Commentary or Exposition upon All the Books of the Old and New Testament (1647–1656) — public domain. Text from a community e-Sword module.

Lev 18:14. Thy father’s brother — Thou shalt not marry thy uncle’s wife, as is explained in the next words.

Joseph Benson's Commentary on the Old and New Testaments (1811–1818) — public domain. Text from a community e-Sword module.

18:14 Having sexual relations with your aunt would dishonor your uncle. In turn, this would also dishonor your father (see 20:20).

Tyndale Open Study Notes — © Tyndale Open Resources, licensed CC BY-SA 4.0. Text via the HelloAO Bible API.

Which thine uncle doth discover.

Hebrew, thy father’s brother’s wife.

Geneva Bible (1599) marginal notes — public domain. Text via Bolls.life.

(14) Thy father’s brother, thou shalt not approach to his wife.—That is, according to the ancient legal interpretation, a nephew is to have no commerce with her during her husband’s lifetime, nor marry her when his uncle is dead. Those who transgressed this law had not only to bear their sin, but were doomed to die without issue. (See Lev_20:20.)

A Bible Commentary for English Readers, edited by Charles John Ellicott (1878–1897) — public domain. Text from a community e-Sword module.

Thou shalt not uncover the nakedness of thy father's brother,.... Which Gersom understands of committing sodomy with him, on which account he was doubly guilty, partly because of lying with a male, and partly because of uncovering the nakedness of his father's brother; but it rather seems at first sight as if the sense was, that a woman should not marry her father's brother, that is, her uncle, as a man might not marry his aunt, whether by father or mother's side, as in Lev 18:12; but Jarchi directs to a better sense than either, when he asks, what is his nakedness? in answer to which he recites the following clause as explanative of it:

thou shall not approach to his wife; in the use of the bed, as the Targum of Jonathan adds, that is, to lie with her, her husband being living, or to marry her, he being dead:

she is thine aunt: even as a father's or mother's sister, only they are aunts by blood, this by marriage or affinity: in the Targums of Onkelos and Jonathan it is, she is the wife of thy father's brother; and as Aben Ezra, she is accounted as thine aunt, and so marriage with her prohibited; and the same holds good of a father's brother's wife, which being not mentioned, the same writer says, we have need of the tradition which expresses that and also of a father's sister's husband; for if marriage with a father's brother's wife is unlawful, then marriage with a father's sister's husband must be so too; for a father's sister's husband stands in the same degree or line of affinity as a father's brother's wife; and it is a sure rule, that in whatsoever degree or line of affinity males are forbid to marry females, in the same females are forbid to marry males.

John Gill's Exposition of the Whole Bible (1746–1763) — public domain (CC PDM 1.0). Text via the HelloAO Bible API.

Who....affinity. Hebrew, "she is thy aunt." Some say that, in the old law, a person might marry his niece, but not his aunt; as the order of nature would be inverted if the aunt were subject to her nephew. But others assert that the law was reciprocal, and excluded the marriage of both. The emperor Claudius married his niece Agrippina, and authorized others to do the like. But only one imitated him at Rome; (Suetonius) though Tacitus (An. xii.) says, other nations did it with solemnity, as they had no law to the contrary. Aliis gentibus solemnia, &c. (Calmet)

George Leo Haydock (1774–1849), Haydock's Catholic Family Bible and Commentary, 1859 edition — public domain. Excludes Psalms (Douay-Rheims chapter numbering differs from Protestant) and Deuterocanonical books (Catholic canon only).

Of thy father’s brother, i.e. of his wife, as the next words explain it. And as a man may not marry his aunt, so neither may a woman marry her uncle, there being altogether the same distance in kindred, and the selfsame reason of the law. And for the examples of Abraham, Amram, Othniel, &c., to the contrary, they were before the publication of this law, by which it pleased God to restrain the liberty allowed formerly, when the holy seed was in a narrower compass, and fewer persons, which altered the case. For in that regard there was a time when God allowed brethren and sisters to marry, to wit, when there were no other in the world, which was the case of Adam’s immediate children. We learn from hence that the same degrees are forbidden in consanguinity or kindred by blood, and in affinity or kindred by marriage.

She is thine aunt: some infer from hence that it is unlawful for cousin-germans, or the children of brethren and sisters, to marry. But there is not the same reason, nor the same degree of distance, for my uncle or aunt are nearer akin to me than their children are. Yet because it seems doubtful to many, and may hereafter prove occasion of grievous perplexities of mind, especially to tender and scrupulous consciences, Christian prudence directs us to choose the safest way, there being so great a latitude of unquestionable persons.

Matthew Poole's English Annotations on the Holy Bible (1683–1685) — public domain. Text from a community e-Sword/MySword module.

So, again, with the wife of the father's brother, because the nakedness of the uncle was thereby uncovered. The threat held out in Lev 20:19 and Lev 20:20 against the alliances prohibited in Lev 18:12-14, is that the persons concerned should bear their iniquity or sin, i.e., should suffer punishment in consequence (see at Lev 5:1); and in the last case it is stated that they should die childless. From this it is obvious that sexual connection with the sister of either father or mother was not to be punished with death by the magistrate, but would be punished with disease by God Himself.

Keil & Delitzsch — Biblical Commentary on the Old Testament (1861–1891) — public domain (CC PDM 1.0). Text via the HelloAO Bible API. (Old Testament only.)

ערות אחי אביך לא תגלה THE NAKEDNESS OF THY FATHER'S BROTHER THOU SHALT NOT UNCOVER — and what does this "uncovering of his nakedness" mean אל אשתו לא תקרב? THOU SHALT NOT APPROACH TO HIS WIFE.

Rashi on the Tanakh — English translations: “The Judaica Press complete Tanach with Rashi, translated by A. J. Rosenberg” (CC BY 4.0); “Pentateuch with Rashi's commentary by M. Rosenbaum and A.M. Silbermann, 1929-1934” (public domain); “The Metsudah Tanach series, Lakewood, N.J” (CC BY 4.0); and “The Book of Joshua, Metsudah Publications, 1997” (CC BY 4.0). Text via Sefaria.