Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
ahmad-zuhd:1054ʿAbdullāh > Abū ʿĀmir al-ʿAdawī > Dāwud b. Abū al-Furāt > Abū Ghālib a freed slave of Khālid b. ʿAbdullāh al-Qurashī

[Machine] One night before dawn, someone said to Abu Ghālib, "Won't you get up and pray, even if you only recite a third of the Qur'an?" I said, "O Abu ʿAbd al-Raḥmān, dawn is approaching, so how can I recite a third of the Qur'an?" He said, "Verily, Surah Al-Ikhlāṣ (Say, He is Allah, the One) [Surah Al-Ikhlāṣ 1] is equivalent to a third of the Qur'an."  

الزهد لأحمد:١٠٥٤حَدَّثَنَا عَبْدُ اللَّهِ حَدَّثَنَا أَبُو عَامِرٍ الْعَدَوِيُّ أَخْبَرَنِي دَاوُدُ بْنُ أَبِي الْفُرَاتِ عَنْ أَبِي غَالِبٍ مَوْلَى خَالِدِ بْنِ عَبْدِ اللَّهِ الْقُرَشِيِّ قَالَ كَانَ ابْنُ عُمَرَ يَنْزِلُ عَلَيْنَا بِمَكَّةَ وَكَانَ يَتَهَجَّدُ مِنَ اللَّيْلِ فَقَالَ

لِي ذَاتَ لَيْلَةٍ قَبْلَ الصُّبْحِ يَا أَبَا غَالِبٍ أَلَا تَقُومُ تُصَلِّي وَلَوْ تَقْرَأُ بِثُلُثِ الْقُرْآنِ؟ فَقُلْتُ يَا أَبَا عَبْدِ الرَّحْمَنِ قَدْ دَنَا الصُّبْحُ فَكَيْفَ أَقْرَأُ بِثُلُثِ الْقُرْآنِ؟ قَالَ إِنَّ سُورَةَ الْإِخْلَاصِ {قُلْ هُوَ اللَّهُ أَحَدٌ} [الإخلاص 1] تَعْدِلُ ثُلُثَ الْقُرْآنِ