The ruling on one who prays while traveling in a direction other than the qiblah, then it becomes clear to him
Machine translationRead the Arabic original
The questioner : A man prayed while traveling after exerting his effort, and his ijtihad indicated that the qiblah was in this direction, so he prayed. Then it became clear to him afterward that the qiblah was in a different direction.
The Shaykh : Yes. He does not repeat it.
The questioner : And this opinion you mentioned in the detailed explanation, where did it come from?
The Shaykh : Yes.
The questioner : The prayer is valid because he did what was obligatory upon him.
The Shaykh : Fine, his prayer is valid because he did what is obligatory upon him.
The Shaykh : Yes. He does not repeat it.
The questioner : And this opinion you mentioned in the detailed explanation, where did it come from?
The Shaykh : Yes.
The questioner : The prayer is valid because he did what was obligatory upon him.
The Shaykh : Fine, his prayer is valid because he did what is obligatory upon him.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، 928ما الحكم لرجل صلَّى في السفر...📔 الشرح الممتع على زاد المستقنع - ابن عثيمين - مشروع كبار العلماء — youtube.com
The Arabic text is a machine transcription of the audio recording.