"G-D said to Moses: Say to the Kohanim, the sons of
Aaron …A [Jewish] woman who is a prostitute or profaned they
shall not marry, and they shall not marry a [Jewish] woman who is
divorced, because each [Kohen] is sanctified to his G‑d."
...he should realize that his marrying her would expose her to untold harm...
Lubavitcher Rebbe (from a letter):
In all matters of matrimony, the happiness of two partners is involved, and if
there is any issue between them, the happiness of children and future
generations is at stake. Obviously a marriage which is prohibited by the Creator
and Master of the Universe is one that cannot be a happy one, and is certain to
be harmful to all parties. In other words, if the said kohen has feelings
for the divorcee in question, he should realize that his marrying her would
expose her to untold harm not only in the afterlife and in a spiritual sense but
also in this physical life.
The fact that it is beyond comprehension is
immaterial, for it is certain that the Creator of the world knows what is best
for His creatures and since He has so strictly prohibited such a marriage there
can be no doubt that it is harmful. Therefore even on humanitarian grounds, the
said kohen, if he has any feelings for the said divorcee [for that reason
also] should give up the idea and avoid causing himself and her irreparable
damage, physically and spiritually.
Copyright 2001 Chabad of California / http://www.LAchumash.org