The ruling on one who doubts the number of circuits

The questioner:
Please, Ibrahim, come on to the line. Ibrahim. And peace be upon you. The Shaykh’s question. Please go ahead. My mother went on 'Umrah last week. She performed tawaf six times, but she had a doubt about the last one. One of the children was there and said to her, “We have completed seven.” She said, “No, we missed the last one; we did not complete it,” and they left Makkah. What is required of her, O Shaykh?

The Shaykh:
Do you mean you are certain that they did not complete seven circuits?

The questioner:
My mother says she performed tawaf six times, but she had a doubt about the last one, and one of the sons said, “No, we completed it,” meaning they had a doubt about the last one.

The Shaykh:
If they had a doubt and they did not complete the tawaf, it is obligatory for them to complete it. However, if the doubt did not occur until after the completion of the tawaf, it has no effect. Yes.