Q. Why does the Yom Kippur afternoon reading of the Torah deal with forbidden marriages?
A. The reading deals with unacceptable relationships and unapproved sexual conduct.
On the day when we seek forgiveness from all our sins, we have to recognise that many of our worst sins involve impure thoughts, unchaste attitudes, promiscuous conduct, marital unfaithfulness and family disloyalty. All, says the Torah, are so serious that they threaten the stability of society. We cannot talk blithely about sin without facing the reality that there are personal sins that we actually may have committed.
The Tosafot find a spiritual implication in the Minchah reading: “Just as the Holy One, Blessed be He, warned us not to ‘uncover the nakedness’ of those forbidden to us, so do we intimate to God our hope that He will not expose our transgressions to their fullest extent” (Tosafot, Meg. 31a).