What is the ruling when one praying based on taqlid (imitation) of a mujtahid is informed during the prayer that they are facing the wrong Qibla?
Chapter on Facing the Qiblah
Al-Mughni
Book of Prayer
Primary text
If a person praying based on the imitation of a mujtahid is informed during the prayer that they have erred in their Qibla direction, and the informant speaks from certainty (yaqin)—such as claiming to have seen the sun or stars and being certain of the error—the one praying must return to the informant's statement. They must turn towards the direction indicated as the Qibla of the Kaaba. This is because if the informed person were a blind man imitating a mujtahid, the ruling would compel him to accept the informant's testimony, and the situation of the sighted person is analogous. The obligation to change direction is established because the initial action, though based on imitation, is superseded by certain knowledge.
Supporting text
If the informant only conveys their own Ijtihad (independent reasoning) or does not clarify the basis of their knowledge, and the person praying does not feel more certain about the informant than about their original direction, the prayer continues as is. This is because the prayer commenced based on a strong conviction (dalil yaqin), and mere doubt cannot nullify it.