Sayyiduna Abu al-Darda' (may Allah be pleased with him) said: When the Messenger of Allah (peace and blessings be upon him) sat and we sat around him, and he (peace and blessings be upon him) stood up intending to come back, he (peace and blessings be upon him) would leave his sandals or something else at that place; the Companions (may Allah be pleased with them) would understand and remain firmly seated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11840