Muslim bin Yasar and Abdullah bin Ubayd both said: The place where Ubadah and Mu'awiyah (may Allah be pleased with them both) came together was a temple of the Jews or of the Christians. And he mentioned the hadith on currency exchange in full.
Muslim bin Yasar did not hear this hadith from Ubadah bin al-Samit; he only heard it from Abu al-Ash'ath al-San'ani, from Ubadah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10477