وَعَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو رَضِيَ اللَّهُ عَنْهُ قَالَ: رَجَعْنَا مَعَ رَسُولِ اللَّهِ ﷺ مِنْ مَكَّةَ إِلَى الْمَدِينَةِ، حَتَّى إِذَا كُنَّا بِمَاءٍ بِالطَّرِيقِ، تَعَجَّلَ قَوْمٌ عِنْدَ الْعَصْرِ فَتَوَضَّؤُوا وَهُمْ عِجَالٌ، فَانْتَهَيْنَا إِلَيْهِمْ وَأَعْقَابُهُمْ تَلُوحُ لَمْ يَمَسَّهَا الْمَاءُ. فَقَالَ رَسُولُ اللَّهِ ﷺ: وَيْلٌ لِلْأَعْقَابِ مِنَ النَّارِ، أَسْبِغُوا الْوُضُوءَ
Translation: ʿAbd Allah ibn ʿAmr said: We were returning from Mecca to Medina. At water along the road, some people hurried to make ablution near ʿAsr. We reached them while their heels remained dry, untouched by water. The Messenger of Allah ﷺ warned of punishment for the heels and said: “Perform ablution thoroughly.”
ʿAbd Allah ibn ʿAmr relates that, during a journey, some people hurried to make ablution around the time of ʿAsr. When the Prophet ﷺ and his companions caught up with them, parts of their heels were visibly dry. The Prophet ﷺ warned them sharply and commanded thorough ablution.
تَعَجَّلَ means “hurried,” عِجَالٌ “in haste,” أَعْقَابُهُمْ “their heels,” and لَمْ يَمَسَّهَا الْمَاءُ “water had not touched them.” The defect arose from incomplete washing, not from travel itself.
Source: Muslim