Short answer
Many sahih hadith praise wudu: sins leave with the water, the believers will be known on the Day of Judgement by the light on their faces, hands and feet, and the gates of Paradise open for one who makes wudu well and then says the shahada. Wudu is fard for prayer and earns reward in its own right.
Wudu is fard for salah and for touching the Quran, and required for tawaf. It is mustahabb at many other times, such as before sleep and when renewing purity. The reward in these hadith is tied to completing wudu well, with its sunnahs.
The four schools agree on this.
Explanation
The hadith on wudu (ablution) fall into a few themes. Here are the best known, from Sahih al-Bukhari and Sahih Muslim.
- Sins wash away. When a Muslim washes his face, every sin his eyes looked at leaves with the water, and the same for his hands and feet, until he finishes cleansed of sins.
- Light on the Day of Judgement. The Prophet ﷺ said his ummah will be called on that Day with shining faces, hands and feet from the traces of wudu.
- Forgiveness through two rak'ahs. Uthman demonstrated the wudu of the Prophet and reported that whoever makes wudu like it and prays two rak'ahs with focus is forgiven past sins.
- The gates of Paradise. Whoever makes wudu well and then says the shahada has all eight gates of Paradise opened for him.
- Half of faith. Purity is half of faith.
Scholars explain that the sins wiped away this way are minor ones; major sins need tawbah (repentance). The hadith also show that how you make wudu matters: doing it fully, calmly and with its sunnahs is what the reward is tied to. The four schools agree on these virtues. See the sunnahs of wudu and the dua after wudu.
For more on purity in the hadith, see hadith about cleanliness, and for the steps, how to make wudu.
The evidence
Quran, Surah Al-Maaida 5:6
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِذَا قُمْتُمْ إِلَى ٱلصَّلَوٰةِ فَٱغْسِلُوا۟ وُجُوهَكُمْ وَأَيْدِيَكُمْ إِلَى ٱلْمَرَافِقِ وَٱمْسَحُوا۟ بِرُءُوسِكُمْ وَأَرْجُلَكُمْ إِلَى ٱلْكَعْبَيْنِ ۚ وَإِن كُنتُمْ جُنُبًۭا فَٱطَّهَّرُوا۟ ۚ وَإِن كُنتُم مَّرْضَىٰٓ أَوْ عَلَىٰ سَفَرٍ أَوْ جَآءَ أَحَدٌۭ مِّنكُم مِّنَ ٱلْغَآئِطِ أَوْ لَٰمَسْتُمُ ٱلنِّسَآءَ فَلَمْ تَجِدُوا۟ مَآءًۭ فَتَيَمَّمُوا۟ صَعِيدًۭا طَيِّبًۭا فَٱمْسَحُوا۟ بِوُجُوهِكُمْ وَأَيْدِيكُم مِّنْهُ ۚ مَا يُرِيدُ ٱللَّهُ لِيَجْعَلَ عَلَيْكُم مِّنْ حَرَجٍۢ وَلَٰكِن يُرِيدُ لِيُطَهِّرَكُمْ وَلِيُتِمَّ نِعْمَتَهُۥ عَلَيْكُمْ لَعَلَّكُمْ تَشْكُرُونَ ﴿٦﴾
O you who have believed, when you rise to [perform] prayer, wash your faces and your forearms to the elbows and wipe over your heads and wash your feet to the ankles. And if you are in a state of janabah, then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it. Allah does not intend to make difficulty for you, but He intends to purify you and complete His favor upon you that you may be grateful.
Wudu is a purification and a favour from Allah, not a burden.
Sahih Muslim 244
Sahih... فغسل وجهه خرج من وجهه كل خطيئة نظر إليها بعينيه ...
"When he washes his face, every sin he looked at with his eyes leaves his face."
Wudu removes minor sins.
Sahih al-Bukhari 136
Sahih... إن أمتي يدعون يوم القيامة غرا محجلين من آثار الوضوء ...
"My ummah will be called on the Day of Resurrection with shining faces, hands and feet from the traces of wudu."
Wudu marks the believers on the Day of Judgement.
Sahih Muslim 234
Sahih... إلا فتحت له أبواب الجنة الثمانية يدخل من أيها شاء ...
"The eight gates of Paradise are opened for him, to enter by whichever he wishes."
The reward for wudu done well followed by the shahada.
Sahih Muslim 223
Sahih... الطهور شطر الإيمان والحمد لله تملأ الميزان ...
"Purity is half of faith, and alhamdulillah fills the scale."
The place of purity in the religion.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Kitab al-Taharah, section on when wudu is fard, wajib and recommended. When wudu is required and when it is recommended.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.