Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
tabarani:9178ʿAlī b. ʿAbd al-ʿAzīz > Abū Nuʿaym > Ḥumayd b. ʿAbdullāh al-Aṣam > Abū Qays

[Machine] Abdullah entered the mosque on Friday wearing clean white clothes. He looked for a spacious place and sat down without pushing anyone. When the Imam came out, he saw two men talking, so he took a pebble and threw it at them. They looked at him and became silent. When the Imam finished his sermon, he said, "Didn't you know that you were in prayer?"  

الطبراني:٩١٧٨حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ الْعَزِيزِ ثنا أَبُو نُعَيْمٍ ثنا حُمَيْدُ بْنُ عَبْدِ اللهِ الْأَصَمُّ عَنْ أَبِي قَيْسٍ قَالَ

دَخَلَ عَبْدُ اللهِ يَوْمَ الْجُمُعَةِ الْمَسْجِدَ وَعَلَيْهِ ثِيَابٌ بِيضٌ نَقَاءٌ حِسَانٌ فَنَظَرَ إِلَى مَكَانٍ فِيهِ سَعَةٌ فَجَلَسَ وَلَمْ يَتَخَطَّ أَحَدًا قَالَ وَخَرَجَ الْإِمَامُ فَإِذَا رَجُلَانِ يَتَكَلَّمَانِ فَأَخَذَ مِنَ الْحَصَا فَرَمَاهُمَا فَنَظَرَا إِلَيْهِ فَسَكَتَا فَلَمَّا نَزَلَ الْإِمَامُ قَالَ «أَلَمْ تَعَلْمَا أَنَّكُمَا فِي صَلَاةٍ»