Is it legislated to seek forgiveness three times before embarking on an important task, and what is its wording as وردed in the Sunnah? And is consistently doing so considered an innovation (bid‘ah), and why do some officiants (ma’dhunin) request the recitation of Al-Fatiha and seeking forgiveness during the marriage contract?

Seeking forgiveness (Istighfar) is prescribed at all times and without restriction, except for what has been authentically reported in the Sunnah, as it is a means of drawing closer to Allah through permissible and recommended deeds. It has many forms, including: "Astaghfirullah (I seek forgiveness from Allah)," and the master of seeking forgiveness (Sayyid al-Istighfar): "Allahumma anta Rabbi la ilaha illa Anta... (O Allah, You are my Lord, there is no god but You...)." Among its forms are: "Astaghfirullah al-Azim al-ladhi la ilaha illa Huwa al-Hayy al-Qayyum wa atubu ilayh (I seek forgiveness from Allah, the Magnificent, whom there is no god but Him, the Ever-Living, the Sustainer, and I repent to Him)," and "Ghufranaka (Your forgiveness)" after leaving the restroom, and the supplication for entering and exiting the mosque: "Rabbighfir li dhunubi waftah li abwaba rahmatik/fadlik (My Lord, forgive my sins and open for me the gates of Your mercy/bounty)," and saying "Rabbighfir li (My Lord, forgive me)" between the two prostrations. However, specifying a certain number for seeking forgiveness or linking it to a specific act without a textual religious basis is an innovation.