Ibn "Abbas said : I used to know by it when they finished the prayer and would listen to it (making the mention of Allah).
In-book : Book 2, Hadith 614
English translation : Book 2, Hadith 998
2. Prayer (Kitab Al-Salat)
باب التَّكْبِيرِ بَعْدَ الصَّلاَةِ