Sayyiduna Abu Hurayrah (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Among the Children of Israel there was a merchant whose trade would sometimes decrease and at other times increase. He thought: 'There is no good in this trade; I must seek a trade that is better than this.' So he built a hermitage and took up a life of monasticism in it. His name was Jurayj."
Ahmad recorded it, and its chain is jayyid (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 18061