We knew the finishing of the prayer of the Messenger of Allah ﷺ through takbir. 'Amr (b. Dinar) said: I made a mention of it to Abu Mas'ud. hue he rejected it and said: I never narrated it to you. 'Amr said: He did narrate it before this. (Using translation from Muslim 583b)
«مَا كُنَّا نَعْرِفُ انْقِضَاءَ صَلَاةِ رَسُولِ اللهِ ﷺ إِلَّا بِتَكْبِيرِهِ»
I used to recognize the completion of the prayer of the Prophet ﷺ by hearing Takbir.
كُنْتُ أَعْرِفُ انْقِضَاءَ صَلاَةِ النَّبِيِّ ﷺ بِالتَّكْبِيرِ
The end of the prayer of the Messenger of Allah ﷺ was known by the takbir (pronounced aloud).
كَانَ يُعْلَمُ انْقِضَاءُ صَلاَةِ رَسُولِ اللَّهِ ﷺ بِالتَّكْبِيرِ
"I used to know that the prayer of the Messenger of Allah ﷺ ended by the takbir." (Using translation from Nasāʾī 1335)
مَا كُنْتُ أَعْرِفُ انْقِضَاءَ صَلاةِ رَسُولِ اللهِ ﷺ إِلا بِالتَّكْبِيرِ
I used to recognize the completion of the prayer of the Prophet ﷺ by hearing Takbir. (Using translation from Bukhārī 842)
«كُنْتُ أَعْرِفُ انْقِضَاءَ صَلَاةِ رَسُولِ اللَّهِ ﷺ بِالتَّكْبِيرِ»