Sahih Bukhari | Volume 7 | Hadith Number 250

Narrated by Yunus Ibn Jubair
Ibn 'Umar divorced his wife while she was having her menses. 'Umar asked the Prophet who said, "Order him (your son) to take her back, and then divorced her before her period of the 'Iddah has elapsed." I asked Ibn 'Umar, "Will that divorce (during the menses) be counted?" He replied, "If somebody behaves foolishly (will his foolishness be an excuse for his misbehaviour)?"