An-Nisaa (The Women)

129. "You will never be able to deal equitably between (your) wives, however much you be eager (to do so); then do not incline with a total inclination (to one) so that you leave her as it were in suspense; and if you effect reconciliation and keep from evil, then verily Allah is Forgiving, Merciful."

Heavenly Law Has no Contradiction with Natural Disposition

It is natural that a man shows more affection to his young wife than his aged wife. That is why the commandment of Justice is only due to the treatment of man unto his wives, not due to his heartily love.

"You will never be able to deal equitably between (your) wives...."

Now that heartily justice is not possible, then, there should be equity in action.

In Islam, there is no duty beyond the ability of a person. A human being is not usually able to adjust affection, but he is able to apply justice in dealing the affairs.

It is unlawful for a man to leave his wife undecided.

"... then do not incline with a total inclination (to (one) so that you leave her as it were in suspense;

Through reconciliation and piety, both the former shortcomings and the unconscious negligence will be forgiven.

"... and if you effect reconciliation and keep from evil, then verily Allah is Forgiving, Merciful."