What is the ruling on converting an obligatory prayer into a voluntary one?
Machine translationRead the Arabic original
The questioner : Is it permissible for the one praying to convert his obligatory prayer into a voluntary one?
The Shaykh : Yes.
The questioner : The one behind you.
The Shaykh : Absolutely, or with a condition?
The questioner : Thank you.
The Shaykh : This is one; the second condition
The questioner : Yes.
The Shaykh : Yes.
The questioner : is that he is praying alone. Now, what is it?
The Shaykh : That the voluntary prayer it is converted into is not specified.
The questioner : Yes, absolutely?
The Shaykh : To a specified one, it does not work.
The questioner : Good.
The Shaykh : That specified one is not valid, but it is valid to convert the obligatory prayer into a voluntary one.
The Shaykh : Yes.
The questioner : The one behind you.
The Shaykh : Absolutely, or with a condition?
The questioner : Thank you.
The Shaykh : This is one; the second condition
The questioner : Yes.
The Shaykh : Yes.
The questioner : is that he is praying alone. Now, what is it?
The Shaykh : That the voluntary prayer it is converted into is not specified.
The questioner : Yes, absolutely?
The Shaykh : To a specified one, it does not work.
The questioner : Good.
The Shaykh : That specified one is not valid, but it is valid to convert the obligatory prayer into a voluntary one.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، 935هل يجوز للمصلِّي أن يقلب...📔 الشرح الممتع على زاد المستقنع - ابن عثيمين - مشروع كبار العلماء — youtube.com
The Arabic text is a machine transcription of the audio recording.