Sayyiduna Umar (may Allah be pleased with him) says that the last verse revealed in the Noble Qur'an was regarding usury, so the Prophet (peace and blessings be upon him) did not get the opportunity to fully explain it before his blessed passing. Therefore, abandon usury as well, and leave whatever contains even a little doubt.
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 350
Hadith Gradingحکم دارالسلام:حسن، سعيد بن المسيب لم يسمع من عمر