Abu Huraira on Hadith: I spend a third of the night remembering Hadith

Al-Darimi reported: Abu Huraira, may Allah be pleased with him, said, “I have divided the night into three parts. I sleep in a third of it, I stand in prayer for a third of it, and for a third of it I recall the traditions of the Messenger of Allah, peace and blessings be upon him.”

Source: Sunan al-Dārimī 264

عن الدارمي قَالَ أَبُو هُرَيْرَةَ رضي الله عنه إِنِّي لَأُجَزِّئُ اللَّيْلَ ثَلَاثَةَ أَجْزَاءٍ فَثُلُثٌ أَنَامُ وَثُلُثٌ أَقُومُ وَثُلُثٌ أَتَذَكَّرُ أَحَادِيثَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ

264 سنن الدارمي المقدمة باب العمل بالعلم وحسن النية فيه