All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
The Prophet said, “Do not make your homes as graves; indeed the devil flees from the house in which Soorah Al-Baqarah is read." [Muslim]
The apparent meaning of this hadeeth is reciting the entire Soorah, and not only part of it. The author of Tuhfat-ul-Ahwathi said, “He (the Prophet) particularly singled out Soorah Al-Baqarah because of its length and great status, and because of the numerous rulings that it contains…”
Ibn Baaz said, “It appears – and Allah knows best – that the benefit is achieved by reciting Soorah Al-Baqarah in full, either from a radio or by the person living in the house.”
If the Soorah is recited by night, it is hoped that its effectiveness applies to the day, Allah willing, for up to three days, and if it is recited during the day, its effectiveness also applies to the night, Allah willing, for up to three nights.
Ibn Hibbaan reported – with a weak chain of narrators – that the Prophet said, “Whoever recites Soorah Al-Baqarah in his home by night, the devil will not enter his house for three nights, and whoever recites it during the day, the devil will not enter his house for three days.”
It was also reported that reciting the last two verses from Soorah Al-Baqarah for three nights prevents the devil from entering the house, Allah willing. An-Nu'maan ibn Basheer narrated that the Prophet said, “Verily, Allah wrote a book two thousand years before he created the heavens and the earth; from it, He sent down two verses with which He concluded Soorah Al-Baqarah. The devil cannot approach a house in which they are recited for three nights.” [Ahmad, with a good chain of narrators]
Allah knows best.