What is the ruling regarding a man who divorced his wife due to adultery, then married another woman, and then returned to the first wife?

A man divorcing his wife for committing adultery is permissible and even recommended, according to Ibn Qudamah, who stated that divorce is recommended when a woman neglects God's rights or is unchaste. As for him taking her back after the divorce, it is permissible if she repents from the adultery, whether within the 'iddah (waiting period) or afterwards with a new contract. He must then be just between his two wives in terms of division [of time/lodging] and maintenance.