فَإِنْ عَلِمَ أَنَّهُ أَخْطَأَ بَعْدَ مَا صَلَّى فَلَا إِعَادَةَ عَلَيْهِ
Translation: If, after completing the prayer, he learns that his direction was mistaken, no repetition is required.
This applies to someone who made a genuine, reasonable effort to determine direction and then completed prayer.
The subsequent discovery of error does not require repetition. The dispensation does not license deliberately neglecting available means of finding the qiblah.
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Conditions of Prayer: Purity, Covering, Intention and Qiblah
فَإِنْ عَلِمَ أَنَّهُ أَخْطَأَ بَعْدَ مَا صَلَّى فَلَا إِعَادَةَ عَلَيْهِ
Translation: If, after completing the prayer, he learns that his direction was mistaken, no repetition is required.
This applies to someone who made a genuine, reasonable effort to determine direction and then completed prayer.
The subsequent discovery of error does not require repetition. The dispensation does not license deliberately neglecting available means of finding the qiblah.