Sufyan said that Ibn Shubrumah said: I considered how much of the Qur'an would suffice a man, and I found no surah of fewer than three verses. So I said: It is not proper then to recite fewer than three verses.
(b) Abd al-Rahman bin Yazid narrates from Sayyiduna Abu Mas'ud (may Allah be pleased with him), who traces it back to the Prophet (peace and blessings be upon him): "Whoever recites two verses of Surah al-Baqarah at night, they will suffice him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4761