Sahih al-Bukhari Book 34, Hadith 53
We set out with Allah's Messenger (ﷺ) in the year of Hunain, (the Prophet (ﷺ) gave me an armor). I sold that
armor and bought a garden in the region of the tribe of Bani Salama and that was the first property I
got after embracing Islam.
Here (i.e. in Mecca) there was a man called Nawwas and he had camels suffering from the disease of excessive and unquenchable thirst. Ibn `Umar went to the partner of Nawwas and bought those camels. The man returned to Nawwas and told him that he had sold those camels. Nawwas asked him, "To whom have you sold them?" He replied, "To such and such Sheikh." Nawwas said, "Woe to you; By Allah, that Sheikh was Ibn `Umar." Nawwas then went to Ibn `Umar and said to him, "My partner sold you camels suffering from the disease of excessive thirst and he had not known you." Ibn `Umar told him to take them back. When Nawwas went to take them, Ibn `Umar said to him, "Leave them there as I am happy with the decision of Allah's Messenger (ﷺ) that there is no oppression . "
Allah's Messenger (ﷺ) said, "The example of a good companion (who sits with you) in comparison with a bad one, is like that of the musk seller and the blacksmith's bellows (or furnace); from the first you would either buy musk or enjoy its good smell while the bellows would either burn your clothes or your house, or you get a bad nasty smell thereof."