It is narrated from Musayyib bin Rafi’ (may Allah have mercy on him) or someone else (Hammad is unsure) that whoever recites Surah ﴿إِذَازُلْزِلَتِ﴾, it is as if he has recited half of the Qur’an; and whoever recites Surah ﴿قُلْيَاأَيُّهَاالْكَافِرُونَ﴾, it is as if he has recited a quarter of the Qur’an; and whoever recites Surah ﴿قُلْهُوَاللهُأَحَدٌ﴾, it is as if he has recited a third of the Qur’an.
Hadith Referenceسنن سعید بن منصور / كتاب التفسير / 73