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.
darimi:272

[Machine] He informed us and Abu Huraira said, "Indeed, I divide the night into three parts. I sleep for one third, I stand in worship for one third, and I remember the sayings of the Messenger of Allah, peace be upon him, for one third."  

الدارمي:٢٧٢

أَخْبَرَنَا وَقَالَ أَبُو هُرَيْرَةَ إِنِّي لَأُجَزِّئُ اللَّيْلَ ثَلَاثَةَ أَجْزَاءٍ فَثُلُثٌ أَنَامُ وَثُلُثٌ أَقُومُ وَثُلُثٌ أَتَذَكَّرُ أَحَادِيثَ رَسُولِ اللَّهِ ﷺ