It was narrated from Ibn ‘Abd Khair that his father said:

I saw ‘Ali (رضي الله عنه) do wudoo’, and he washed the tops of his feet and said: Were it not that I saw the Messenger of Allah (ﷺ) wash the tops of his feet, I would have thought that the bottoms of the feet were more deserving of being washed.

حَدَّثَنَا عَبْد اللَّهِ، حَدَّثَنَا إِسْحَاقُ بْنُ إِسْمَاعِيلَ، حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي السَّوْدَاءِ، عَنِ ابْنِ عَبْدِ خَيْرٍ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ عَلِيًّا رَضِيَ اللَّهُ عَنْهُ تَوَضَّأَ فَغَسَلَ ظَهْرَ قَدَمَيْهِ وَقَالَ لَوْلَا أَنِّي رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَغْسِلُ ظُهُورَ قَدَمَيْهِ لَظَنَنْتُ أَنَّ بُطُونَهُمَا أَحَقُّ بِالْغَسْلِ‏.‏