Sunan Ibn Majah, Book 37, Hadith 4361 (In-Book) ⓘ
It was narrated from Abu Bakr bin Abu Zuhair Ath-Thaqafi, that his father said: “The Messenger of Allah addressed us in Nabawah” or Banawah – he (one of the narrators) said: “Nabawah is near Ta’if” – “And said: ‘Soon you will be able to tell the people of Paradise from the people of Hell.’ They said: ‘How O Messenger of Allah?’ He said: ‘By praise and condemnation. You are Allah’s witnesses over one another.’”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، أَنْبَأَنَا نَافِعُ بْنُ عُمَرَ الْجُمَحِيُّ، عَنْ أُمَيَّةَ بْنِ صَفْوَانَ، عَنْ أَبِي بَكْرِ بْنِ أَبِي زُهَيْرٍ الثَّقَفِيِّ، عَنْ أَبِيهِ، قَالَ خَطَبَنَا رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ بِالنَّبَا أَوِ النَّبَاوَةِ - قَالَ وَالنَّبَاوَةُ مِنَ الطَّائِفِ - قَالَ " يُوشِكُ أَنْ تَعْرِفُوا أَهْلَ الْجَنَّةِ مِنْ أَهْلِ النَّارِ " . قَالُوا بِمَ ذَاكَ يَا رَسُولَ اللَّهِ . قَالَ " بِالثَّنَاءِ الْحَسَنِ وَالثَّنَاءِ السَّيِّئِ أَنْتُمْ شُهَدَاءُ اللَّهِ بَعْضُكُمْ عَلَى بَعْضٍ " .
also referenced under: Hadith 4221 (Reference) & Volume 5, Book 37, Hadith 4221 (DarusSalam)