Sayyiduna Ka'b bin Malik (may Allah be pleased with him) narrates: When the Prophet (peace and blessings be upon him) returned from pursuing the Confederates and came to Madinah, he took off his weapons, performed a ritual bath (ghusl) and used clods (istijmar).
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators are thiqat (trustworthy).