What is the ruling if a husband swears, "Every time I have intercourse with one of you, the co-wives are divorced"?

Primary text

If the oath is considered *Ila'* (a vow of abstinence), the husband enters a state of *Ila'* regarding all of them. This is because he cannot have intercourse with any one wife without divorcing her co-wives, so he is put under a waiting period concerning them. If he returns to having intercourse with one wife, her co-wives are divorced. If the divorce is irrevocable (*bain*), the *Ila'* obligation is lifted because he is no longer prevented from intercourse with her by the ruling of his oath. If the divorce is revocable (*raj'i*), and he revokes the divorce, the ruling of *Ila'* remains concerning the other wives because having intercourse with one requires divorcing the others.