Is it permissible for a husband to refrain from sleeping next to his wife, claiming there is no Quranic verse or Prophetic Hadith commanding it, and that necessity permits the forbidden because he cannot sleep next to anyone?

It is commendable for a husband to sleep with his wife in one bed, as this is part of the good companionship enjoined by Allah Almighty. It is also from the guidance of the Prophet (peace be upon him), who used to sleep with his wives in a single garment, even when they were menstruating. The couple sleeping together strengthens intimacy and affection and prevents problems. Patience and gentle persuasion should be exercised when discussing this matter with the husband.