What is the ruling if the one praying limits himself to the tashahhud without sending blessings upon the Prophet (peace and blessings be upon him)?
Machine translationRead the Arabic original
The questioner : If we say that we pray with the tashahhud without sending blessings upon the Messenger of Allah.
The Shaykh : If we say that it is a sunnah (recommended practice), then it is valid.
The questioner : Yes.
The Shaykh : It is not valid if done intentionally, and if it is due to forgetfulness, the sujud al-sahw (prostration for forgetfulness) is sufficient for it. And if we say that it is a pillar, then one must perform it; so he returns to his prayer, performs it, says the taslim (closing salam), and then performs the prostration for forgetfulness.
The questioner : We give you the new salam.
The Shaykh : No, no, no, yes, with what you omitted, with what you omitted, and what follows.
The Shaykh : If we say that it is a sunnah (recommended practice), then it is valid.
The questioner : Yes.
The Shaykh : It is not valid if done intentionally, and if it is due to forgetfulness, the sujud al-sahw (prostration for forgetfulness) is sufficient for it. And if we say that it is a pillar, then one must perform it; so he returns to his prayer, performs it, says the taslim (closing salam), and then performs the prostration for forgetfulness.
The questioner : We give you the new salam.
The Shaykh : No, no, no, yes, with what you omitted, with what you omitted, and what follows.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، 952 - ما الحكم لو اقتصر المصلي على التشهد دون الصلاة على النبي ﷺ؟ ابن عثيمين — youtube.com
The Arabic text is a machine transcription of the audio recording.