كتاب الطهارة
2  
The Book of Purification
(12)
Chapter: The recommendation to increase the area washed for the forehead, arms, and legs well when performing wudu’
(12)
باب اسْتِحْبَابِ إِطَالَةِ الْغُرَّةِ وَالتَّحْجِيلِ فِي الْوُضُوءِ ‏‏
Sahih Muslim 247b

Abu Huraira reported the Messenger of Allah (ﷺ) said:

My people would come to me on the Cistern and I would drive away persons (from it) just as a person drives away other people's camels from his camels. They (the hearers) said: Apostle of Allah, would you recognize us? He replied: Yea, you would have a mark which other people will not have. You would come to me with a white blaze on your foreheads and white marks on your feet because of the traces of ablution. A group among you would be prevented from coming to me, and they would not meet me, and I would say: O my Lord, they are my companions. Upon this an angel would reply to me saying: Do you know what these people did after you.
حَدَّثَنَا أَبُو كُرَيْبٍ، وَوَاصِلُ بْنُ عَبْدِ الأَعْلَى، - وَاللَّفْظُ لِوَاصِلٍ - قَالاَ حَدَّثَنَا ابْنُ فُضَيْلٍ، عَنْ أَبِي مَالِكٍ الأَشْجَعِيِّ، عَنْ أَبِي حَازِمٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ تَرِدُ عَلَىَّ أُمَّتِي الْحَوْضَ وَأَنَا أَذُودُ النَّاسَ عَنْهُ كَمَا يَذُودُ الرَّجُلُ إِبِلَ الرَّجُلِ عَنْ إِبِلِهِ ‏"‏ ‏.‏ قَالُوا يَا نَبِيَّ اللَّهِ أَتَعْرِفُنَا قَالَ ‏"‏ نَعَمْ لَكُمْ سِيمَا لَيْسَتْ لأَحَدٍ غَيْرِكُمْ تَرِدُونَ عَلَىَّ غُرًّا مُحَجَّلِينَ مِنْ آثَارِ الْوُضُوءِ وَلَيُصَدَّنَّ عَنِّي طَائِفَةٌ مِنْكُمْ فَلاَ يَصِلُونَ فَأَقُولُ يَا رَبِّ هَؤُلاَءِ مِنْ أَصْحَابِي فَيُجِيبُنِي مَلَكٌ فَيَقُولُ وَهَلْ تَدْرِي مَا أَحْدَثُوا بَعْدَكَ ‏"‏ ‏.‏
Reference : Sahih Muslim 247b
In-book reference : Book 2, Hadith 49
USC-MSA web (English) reference : Book 2, Hadith 480
  (deprecated numbering scheme)