What is required of one who exerted effort but did not discern the truth?
Machine translationRead the Arabic original
The questioner : Yes. If a person exerts effort in a matter and the truth does not become clear to him, he must exert effort, but the truth did not become clear.
The Shaykh : Now, if the truth did not become clear to him, he is more excused than if he had discerned the error, because 'Ammar discerned the error, and yet the Prophet (peace and blessings be upon him) did not order him to make up the prayers.
The Shaykh : Now, if the truth did not become clear to him, he is more excused than if he had discerned the error, because 'Ammar discerned the error, and yet the Prophet (peace and blessings be upon him) did not order him to make up the prayers.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، 462 - 4600 ماذا على من اجتهد ولم يتبين له الصواب؟ ابن عثيمين — youtube.com
The Arabic text is a machine transcription of the audio recording.