Why is there no hadd (prescribed penalty) or ruling for rape in Islamic Sharia, and what is the punishment for the rapist?

If rape is the act of the abomination of adultery committed under duress, then this is a grave crime whose worldly punishment is one hundred lashes for the virgin, and stoning for the married person, if the conditions are met. The rapist must pay the full dowry, and the woman must perform istibra' (wait for the passing of three menstrual cycles).

If the intention is to enjoy a foreign woman without intercourse, it is forbidden, but its perpetrator is not subject to the Shar'i (legal) hadd (prescribed punishment). Instead, he is subject to a discretionary punishment (ta'zir) as deemed appropriate by the judge.

Thus, crimes are not devoid of punishment. Whatever the Shar' (Islamic law) has prescribed a hadd for, that is applied. For whatever it has not prescribed, the matter is left to the judge's ijtihad (independent reasoning).