Bishr bin Harb narrates: I asked Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): May I take one dirham for two dirhams? He said: This is usury itself (riba); do not even go near it. Do you not know what the Prophet (peace and blessings be upon him) said? He (peace and blessings be upon him) said: Exchange like for like.
Al-Tabarani recorded it in al-Mu'jam al-Kabir. The narrator Bishr bin Harb is da'if (weak), and he has been given a soft (weak) declaration of trustworthiness.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6568