Sahih al-Bukhari 4846
In-book no 4846حَدَّثَنَا عَلِيٌّ، حَدَّثَنَا سُفْيَانُ، قَالَ لِي ابْنُ شُبْرُمَةَ نَظَرْتُ كَمْ يَكْفِي الرَّجُلَ مِنَ الْقُرْآنِ فَلَمْ أَجِدْ سُورَةً أَقَلَّ مِنْ ثَلاَثِ آيَاتٍ، فَقُلْتُ لاَ يَنْبَغِي لأَحَدٍ أَنْ يَقْرَأَ أَقَلَّ مِنْ ثَلاَثِ آيَاتٍ.
Narrated Sufyan: Ibn Shubruma said, "I wanted to see how much of the Qur'an can be enough (to recite in prayer) and I could not find a Surah containing less than three Verses, therefore I said to myself), "One ought not to recite less than three (Quranic) Verses (in prayer)."