بسم الله الرحمن الرحيم

Ibn Taawoos (rahimahullaah) said: My father (rahimahullaah) said: When you arrive in Makkah sit with Amr Ibn Deenaar, because his ears used to be bounded to the scholars.  He used to sleep one third of the night, spoke (about knowledge in the second) one third and prayed in the (last) third.  Ibn Uyaynah (rahimahullaah) said: I sat with Amr for two years and he never made a statement that harmed me.

[Source: Seeratus Salaf As-Saaleh by: Imaam Ismaaeel Bin Muhammad Bin Fadl Al-Asbahaanee (535AH: Chapter: A mention of those who followed the companions in righteousness]