It is narrated from Sayyiduna Abu Sa‘id Khudri (may Allah be pleased with him) that two men were on a journey. The time for prayer came, and they did not have any water with them. So both of them performed tayammum with clean earth and offered the prayer. Then they found water while the time for prayer still remained. One of them performed ablution and repeated the prayer, while the other did not repeat it. Afterwards, when both of them came to the Messenger of Allah (peace and blessings be upon him) and related the incident, he (peace and blessings be upon him) said to the one who did not repeat the prayer:“You acted according to the Sunnah, and your prayer is valid (it sufficed).”And to the one who repeated the prayer, he said:“For you is double the reward.”