Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) handed the Prophet (peace and blessings be upon him) the dust which he threw toward the polytheists; this happened on the occasion of the Battle of Hunayn.
Al-Bazzar recorded it from Isma'il bin Sayf, who is da'if (weak).