Is temporary marriage (mut'a) permitted in Islam?
There is no doubt that historically temporary marriage was institutionalised by the Quran (4:24). Although it was never abrogated by the Quran, it was abolished due to social necessity following the death of the Prophet. Therefore, in line with the Quran temporary marriage is allowed in essence, so long as the specific conditions legislated by the Prophet are met. These specific conditions include mutual consent, mahr in return for the right of cohabitation, specific time period, binding contract etc.
It should be noted that there is an Islamic duty to honour the law of land and therefore, the social contract of marriage within many Western countries would restrict any extra marital relations, including those that are solemnised through temporary marriage.