Two men performed tayammum and prayed, then found water while there was still time for the prayer. One of them performed wudu and repeated his prayer within the remaining time, while the other did not repeat it. They asked the Prophet ﷺ about this.He said to the one who did not repeat his prayer, "You followed the Sunnah, and your prayer is sufficient for you."To the other he said, "As for you, you have a reward like the share of Jam."
أخبرنا مسلم بن عمرو بن مسلم قال حدثني ابن نافع عن الليث بن سعد عن بكر بن سوادة عن عطاء بن يسار
أن رجلين تيمما وصليا ثم وجدا ماء في الوقت فتوضأ أحدهما وعاد لصلاته ما كان في الوقت ولم يعد الآخر فسألا النبي ﷺ فقال للذي لم يعد أصبت السنة وأجزأتك صلاتك وقال للآخر أما أنت فلك مثل سهم جمع
No references are available.
[Its chain of transmission is hasan] Abu Dawud transmitted it in the Book of Purification, chapter on one who performs tayammum and then finds water after having prayed within the prescribed time, hadith no. 338, from the hadith of Abdullah bin Nafi through this chain. Hakim graded it sahih according to the standard of the two Shaykhs (Bukhari and Muslim), 1/178, and Dhahabi concurred with him.