What is the ruling on someone who forgot the number of circuits (ashwat) during Sa'i between Safa and Marwa, then strove to determine which circuit they were on and completed their Sa'i, then doubted the validity of their Sa'i more than a year later, and what are the resulting doubts concerning the validity of their marriage if the Sa'i occurred before the marriage contract?

The basic principle is that whoever doubts the number of rounds in Sa'y (the ritual circumambulation between Safa and Marwa) or Tawaf (the ritual circumambulation around the Kaaba) should build upon the lesser number and complete the doubtful portion. Some verified scholars, such as Ibn Taymiyyah and Ibn 'Uthaymeen, hold the view that whoever doubts the number of rounds should build upon their strongest presumption, and this is permissible when doubts are numerous.

Therefore, if a person strongly believes in the number of the round they were in and completed their Sa'y based on that, their Sa'y is valid.

As for marriage, if it was concluded before the Hajj or 'Umrah whose validity of Sa'y is doubted, it remains valid and is not annulled, for the default is the validity of marriage when its pillars are met.