In the year of the conquest of Khaibar I went with Allah's Messenger (ﷺ) till we reached As-Sahba' where Allah's Messenger (ﷺ) led the `Asr prayer and asked for the food. Nothing but saweeq was brought and we ate it and drank (water). The Prophet (ﷺ) got up for the (Maghrib) Prayer, rinsed his mouth with water and then led the prayer without repeating the ablution.
Sahih al-Bukhari Book 4, Hadith 81
← Previous Hadith Anas said, "The Prophet (ﷺ) used to perform ablution for every prayer." I asked Anas, "What did you used to do?' Anas replied, "We used to pray with the same ablution until we break it with Hadath."

Sahih al-Bukhari Book 4, Hadith 80 Next Hadith → Once the Prophet, while passing through one of the graveyards of Medina or Mecca heard the voices of two persons who were being tortured in their graves. The Prophet (ﷺ) said, "These two persons are being tortured not for a major sin (to avoid)." The Prophet (ﷺ) then added, "Yes! (they are being tortured for a major sin). Indeed, one of them never saved himself from being soiled with his urine while the other used to go about with calumnies (to make enmity between friends). The Prophet (ﷺ) then asked for a green leaf of a date-palm tree, broke it into two pieces and put one on each grave. On being asked why he had done so, he replied, "I hope that their torture might be lessened, till these get dried."

Sahih al-Bukhari Book 4, Hadith 82