Does intercourse during a religiously forbidden state nullify an oath of abstinence (Ila') and release the husband from it?

Primary text

Intercourse performed during a forbidden state nullifies the oath of Ila' (oath of abstinence) and releases the husband from it. This is the position held by Al-Shafi'i. The forbidden states include intercourse with a wife while she is menstruating (Ha'id), in post-natal bleeding (Nifas), while she is in the state of Ihram for Hajj or Umrah, or while the husband is fasting a mandatory fast (Fard) or is himself in Ihram or performing Zihar (a form of divorce/prohibition). The rationale is that the oath is dissolved because the husband has breached the oath through the act, meaning he is no longer abstaining by the ruling of the oath, similar to when he makes expiation for the oath or when he has intercourse with a sick wife. Ahmad explicitly stated that if one swears an oath and then makes expiation for it, the Ila' is lifted even though he did not fulfill the right of the wife, meaning the Ila' is lifted when the oath itself is removed via the act of breaking it (Hinth).