Imaam Ahmad (rahimahullaah) said:

He was a Shaikh, a righteous person and virtuous person.  Indeed I love Rayyaah, I love his hadeeth and I love a mention of him.

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