Is it permissible for someone who divorced his wife irrevocably (three times in one utterance) and affirmed it legally, to marry her again after ten years?

The fatwa we adopt is that a triple divorce pronounced at once counts as three divorces, and the wife becomes irrevocably divorced (baynunah kubra) thereby. This is the view of most scholars, such as Ibn Qudamah. However, Shaykh al-Islam Ibn Taymiyyah and those who agreed with him held that a triple divorce pronounced at once counts as a single divorce.

Accordingly, your wife has become irrevocably divorced from you (baynunah kubra). You cannot remarry her unless she marries another man in a genuine marriage of desire, and he consummates the marriage with her, and then he divorces her or dies, and her 'iddah (waiting period) ends. We advise you to refer the matter to the Sharia court for a ruling.