It is narrated from Hazrat Salim bin Abdullah that I was traveling with Sayyiduna Abdullah bin Umar (may Allah be pleased with them), and I saw that today when the sun rose, he performed ablution and offered prayer. I said, "Today you have offered a prayer which you did not use to offer." Sayyiduna Abdullah bin Umar (may Allah be pleased with them) said, "Today, after performing ablution, I touched my private part, then I forgot to perform ablution again and I offered the Fajr prayer. That is why I have now performed ablution and repeated the prayer."