صحيح البخاري Sahih Bukhari كتاب الجمعة The Book of Al-Jumuah (Friday)
بَابُ إِذَا رَأَى الإِمَامُ رَجُلاً جَاءَ وَهْوَ يَخْطُبُ أَمَرَهُ أَنْ يُصَلِّيَ رَكْعَتَيْنِ:

(32) Chapter. When the Imam sees a person entering the mosque during the Khutba, he should order him to offer two Raka Salat (prayer) before sitting (Tahayyat-ul-Masjid).

1 hadith
Hadith 930
حَدَّثَنَا أَبُو النُّعْمَانِ ، قَالَ : حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ ، عَنْ عَمْرِو بْنِ دِينَارٍ ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ ، قَالَ : جَاءَ رَجُلٌ وَالنَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَخْطُبُ النَّاسَ يَوْمَ الْجُمُعَةِ ، فَقَالَ : " أَصَلَّيْتَ يَا فُلَانُ ؟ قَالَ : لَا ، قَالَ : قُمْ فَارْكَعْ " .
Narrated Jabir bin `Abdullah: A person entered the mosque while the Prophet was delivering the Khutba on a Friday. The Prophet said to him, "Have you prayed?" The man replied in the negative. The Prophet said, "Get up and pray two rak`at."
Hadith Reference Sahih Bukhari / The Book of Al-Jumuah (Friday) / Hadith: 930
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة