The woman and the man guilty of adultery or fornication, -
flog them each with a hundred stripes.
-- Sura 24:2

If any of your women are guilty of lewdness,
take the evidence of four (reliable) witnesses from amongst you against them;
and if they testify, confine them to houses until death do claim them,
or Allah ordain for them some (other) way.

If two (men) among you are guilty of lewdness, punish them both.
If they repent and amend, leave them alone;
for Allah is Oft-returning, Most Merciful.
-- Sura 4:15-16

Yusuf Ali says "men", other translations just say "two". It is the masculine dual form of the word. This "could" also mean a man and a woman, but it might be more natural as reading this as a rule how to deal with homosexual acts, since verse 15 deals only with women, and so the attention turns to men in verse 16.

If 4:16 is about male homosexual acts, then interestingly, the homosexual men are to be left alone when they repent of their deed, while adulterers are to be punished in any case. This alone is not a contradiction, but certainly strange. Maybe because in an homosexual act no other man's right over a woman is violated? While in adultery with the wife of another man the "property" or right of an undefiled wife of this man is violated?

A homosexual act would violate only the wife of this other man but the violation of a woman is not as severe?

Nevertheless, there is the contradiction whether for a female adulteress the is punishment one hundred stripes [Sura 24:2] or confinement in the house until death [4:15].

If 4:16 does not speak only about homosexual acts but also about adultery of man and woman, then another contradictory element is added: If they repent they can get off the hook without punishment? Who will not repent with the prospect of a hundred stripes waiting for them?

Apart from the question whether the punishment should be as in 24:2 or 4:15, how come the man and woman are treated equal in 24:2, but seemingly different in 4:15?