Leviticus 18:13

Thou shalt not uncover the nakedness of thy mother's sister,
&c.] Which is the same relation as before, an aunt by the mother's side; wherefore, if such a marriage was unlawful, this must also, and for the same reason: for she [is] thy mother's near kinswoman;
the same phraseology is used here as in the preceding verse; (See Gill on Leviticus 18:12); and by the same rule a woman might not marry her uncle, whether by father or mother's side, the relation being the same, and this reaches to great-uncle and great-aunt; instances of women marrying their uncles, and men their aunts, among the Heathens, have been given, as among the Persians and Lacedaemonians by Herodotus ^F12, and among the Romans by Tacitus ^F13, but were, in his time, new things with the latter.