Does stopping the circumambulation (Tawaf al-Ifadah) for a long period—to perform prayer or for other reasons—invalidate the Tawaf, and what is incumbent upon one who did so out of ignorance?

It is permissible to pause the tawaf (circumambulation) to perform an obligatory prayer or the funeral prayer, or to take a place in the prayer line. The tawaf is then resumed from where it stopped. Continuity is not a condition in tawaf, and it is permissible to build upon previous circuits. If the circumambulator pauses and passes the Black Stone, then prays, they may begin the circuit from where they stopped after the prayer, though it is better to return to the Black Stone. If the circumambulator intended to complete the tawaf after the prayer, their previous intention suffices. If the circumambulator completes their Hajj with a farewell tawaf or a voluntary tawaf after the tawaf al-ifadah which had a deficiency, then this tawaf suffices for the tawaf al-ifadah, and their Hajj is valid.