The issue of descending from standing to prostration or sitting without the takbir: why is the takbir omitted when it is obligatory?
Machine translationRead the Arabic original
The questioner : We did not understand. All right.
The Shaykh : I did not understand the reasoning or the ruling. Truly. The ruling is that if you come, whether prostrating or sitting between the two rak'ahs, or sitting for the tashahhud, you say the takbir for the red [marker] and then descend, without the takbir.
The questioner : Who omits it? Yes.
The Shaykh : It is not obligatory.
The questioner : Yes, stupid, stupid.
The Shaykh : There is no prescribed sitting immediately after standing, nor any prescribed prostration immediately after standing. The prescribed prostration after standing is only after a standing that follows a bowing, and here there is no bowing before it. This is the point.
The Shaykh : I did not understand the reasoning or the ruling. Truly. The ruling is that if you come, whether prostrating or sitting between the two rak'ahs, or sitting for the tashahhud, you say the takbir for the red [marker] and then descend, without the takbir.
The questioner : Who omits it? Yes.
The Shaykh : It is not obligatory.
The questioner : Yes, stupid, stupid.
The Shaykh : There is no prescribed sitting immediately after standing, nor any prescribed prostration immediately after standing. The prescribed prostration after standing is only after a standing that follows a bowing, and here there is no bowing before it. This is the point.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، 1249 - مسألة أن ينحط من قيام إلى سجود أو قعود بدون تكبير لماذا سقط التكبير وهو واجب؟ — youtube.com
The Arabic text is a machine transcription of the audio recording.