'Umar b. Khattab said that a person performed ablution and left a small part equal to the space of a nail (unwashed). The Apostle of Allah ﷺ saw that and said: Go back and perform ablution well. He then went back (performed ablution well) and offered the prayer. (Using translation from Muslim 243)
أَنَّ رَجُلًا تَوَضَّأَ فَتَرَكَ مَوْضِعَ ظُفُرٍ عَلَى قَدْمِهِ فَأَبْصَرَهُ النَّبِيُّ ﷺ فَقَالَ ارْجِعْ فَأَحْسِنْ وُضُوءَكَ فَرَجَعَ ثُمَّ صَلَّى
'Umar b. Khattab said that a person performed ablution and left a small part equal to the space of a nail (unwashed). The Apostle of Allah ﷺ saw that and said: Go back and perform ablution well. He then went back (performed ablution well) and offered the prayer.
أَنَّ رَجُلاً تَوَضَّأَ فَتَرَكَ مَوْضِعَ ظُفُرٍ عَلَى قَدَمِهِ فَأَبْصَرَهُ النَّبِيُّ ﷺ فَقَالَ ارْجِعْ فَأَحْسِنْ وُضُوءَكَ فَرَجَعَ ثُمَّ صَلَّى
ʿGo back and do your wudoo’ properly.” So he went back and did wudoo’ then he prayed.
أَخْبَرَهُ أَنَّهُ رَأَى رَجُلًا تَوَضَّأَ لِلصَّلاةِ فَتَرَكَ مَوْضِعَ ظُفْرٍ عَلَى ظَهْرِ قَدَمِهِ فَأَبْصَرَهُ النَّبِيُّ ﷺ فَقَالَ ارْجِعْ فَأَحْسِنْ وُضُوءَكَ فَرَجَعَ فَتَوَضَّأَ ثُمَّ صَلَّى
ʿGo back and do your wudoo' properlyʿ So he went back and did wudoo', then he prayed.
أَخْبَرَهُ أَنَّ رَسُولَ اللهِ ﷺ رَأَى رَجُلًا تَوَضَّأَ لِصَلاةِ الظُّهْرِ فَتَرَكَ مَوْضِعَ ظُفُرٍ عَلَى ظَهْرِ قَدَمِهِ فَأَبْصَرَهُ رَسُولُ اللهِ ﷺ فَقَالَ ارْجِعْ فَأَحْسِنْ وُضُوءَكَ فَرَجَعَ فَتَوَضَّأَ ثُمَّ صَلَّى
"رَأَيْتُ رجلًا توضَّأَ للِصَّلاِة فَتَركَ مَوْضِعَ ظُفُر عَلَى ظَهْر قَدَمِهِ فَأَبْصَرَهُ النَّبِىُّ ﷺ فَقَالَ: ارجعْ فَأَحْسِنْ وَضُوءَكَ، فَرَجعَ فَتوَضَّأَ ثُمَّ صَلَّى".