Sulaym bin Amir (may Allah have mercy on him) said: Sayyiduna Abu Umamah (may Allah be pleased with him) told them that he heard the Messenger of Allah (peace and blessings be upon him) on the day of the Farewell Hajj, while he (peace and blessings be upon him) was on his she-camel al-Jad'a', with his feet placed in the stirrups, one hand resting on the front of the saddle and the other on its back, raising himself up in this way. He (peace and blessings be upon him) said: "O people, be silent, for perhaps you will not see me after this year of yours." Then Allah, the Mighty and Majestic, caused a man from among the people to stand up (to ask), and he asked: "What should we do?" He said: "Worship your Lord, establish your five (prayers), pay the zakah of your wealth, fast your month, and obey those in authority over you; you will enter the Paradise of your Lord."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7645