Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Noble Prophet (peace and blessings of Allah be upon him) said: "When the companion of the Qur'an stands in prayer during the hours of the night and day and recites the Qur'an, he remembers it; otherwise, if he does not stand (in prayer), he forgets it."