"You followed the Sunnah and your prayer is acceptable." And he said to the other: "And you will have something like the reward of two prayers."  

أَنَّ رَجُلَيْنِ تَيَمَّمَا وَصَلَّيَا ثُمَّ وَجَدَا مَاءً فِي الْوَقْتِ فَتَوَضَّأَ أَحَدُهُمَا وَعَادَ لِصَلاَتِهِ مَا كَانَ فِي الْوَقْتِ وَلَمْ يُعِدِ الآخَرُ فَسَأَلاَ النَّبِيَّ ﷺ فَقَالَ لِلَّذِي لَمْ يُعِدْ أَصَبْتَ السُّنَّةَ وَأَجْزَأَتْكَ صَلاَتُكَ وَقَالَ لِلآخَرِ أَمَّا أَنْتَ فَلَكَ مِثْلُ سَهْمِ جَمْعٍ  

Two persons set out on a journey. Meanwhile the time of prayer came and they had no water. They performed tayammum with clean earth and prayed. Later on they found water within the time of the prayer. One of them repeated the prayer and ablution but the other did not repeat. Then they came to the Messenger of Allah ﷺ and related the matter to him. Addressing himself to the one who did not repeat, he said: You followed the sunnah (model behavior of the Prophet) and your (first) prayer was enough for you. He said to the one who performed ablution and repeated: For you there is the double reward. Abu Dawud said: Besides Ibn Nafi' this is transmitted by al-Laith from 'Umairah b. Abi Najiyyah from Bakr b. Sawadah on the authority of 'Ata b. Yasar from the Prophet ﷺ. Abu Dawud said: The mention of (the name of the Companion) Abu Sa'id in this tradition is not guarded. This is a mural tradition (i.e. the Successor 'Ata b. Yasar directly narrates it from the Prophet, leaving the name of the Companion in the chain.)  

خَرَجَ رَجُلاَنِ فِي سَفَرٍ فَحَضَرَتِ الصَّلاَةُ وَلَيْسَ مَعَهُمَا مَاءٌ فَتَيَمَّمَا صَعِيدًا طَيِّبًا فَصَلَّيَا ثُمَّ وَجَدَا الْمَاءَ فِي الْوَقْتِ فَأَعَادَ أَحَدُهُمَا الصَّلاَةَ وَالْوُضُوءَ وَلَمْ يُعِدِ الآخَرُ ثُمَّ أَتَيَا رَسُولَ اللَّهِ ﷺ فَذَكَرَا ذَلِكَ لَهُ فَقَالَ لِلَّذِي لَمْ يُعِدْ أَصَبْتَ السُّنَّةَ وَأَجْزَأَتْكَ صَلاَتُكَ وَقَالَ لِلَّذِي تَوَضَّأَ وَأَعَادَ لَكَ الأَجْرُ مَرَّتَيْنِ  

[Machine] Two men went on a journey. When prayer time came, they did not have water with them. So they performed Tayammum on clean ground and prayed. Later, they found water during the appropriate time. One of them repeated his prayer with ablution, while the other did not repeat it. Then they came to the Messenger of Allah ﷺ and narrated what had happened. He said to the one who did not repeat his prayer, "You have followed the Sunnah and your prayer is accepted." And he said to the one who performed ablution and repeated his prayer, "You will have double the reward."  

خَرَجَ رَجُلَانِ فِي سَفَرٍ فَحَضَرَتْهُمَا الصَّلَاةُ وَلَيْسَ مَعَهُمَا مَاءٌ فَتَيَمَّمَا صَعِيدًا طَيِّبًا فَصَلَّيَا ثُمَّ وَجَدَا الْمَاءَ بَعْدُ فِي الْوَقْتِ فَأَعَادَ أَحَدُهُمَا الصَّلَاةَ بِوُضُوءٍ وَلَمْ يُعِدِ الْآخَرُ ثُمَّ أَتَيَا رَسُولَ اللَّهِ ﷺ فَذَكَرَا ذَلِكَ فَقَالَ لِلَّذِي لَمْ يُعِدْ «أَصَبْتَ السُّنَّةَ وَأَجْزَأتْكَ صَلَاتُكَ» وَقَالَ لِلَّذِي تَوَضَّأَ وَأَعَادَ «لَكَ الْأَجْرُ مَرَّتَيْنِ»