كتاب الطهارة وسننها
1  
The Book of Purification and its Sunnah
(139)
Chapter: One who performed ablution and left a place where water did not reach.
(139)
باب مَنْ تَوَضَّأَ فَتَرَكَ مَوْضِعًا لَمْ يُصِبْهُ الْمَاءُ
Sunan Ibn Majah 665
It was narrated from Anas that:
A man came to the Prophet; he had performed ablution and has missed a spot the size of a fingernail where water had not reached. The Prophet said to him: 'Go back and perform ablution properly.'"
حَدَّثَنَا حَرْمَلَةُ بْنُ يَحْيَى، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، حَدَّثَنَا جَرِيرُ بْنُ حَازِمٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ رَجُلاً، أَتَى النَّبِيَّ ـ صلى الله عليه وسلم ـ وَقَدْ تَوَضَّأَ وَتَرَكَ مَوْضِعَ الظُّفْرِ لَمْ يُصِبْهُ الْمَاءُ فَقَالَ لَهُ النَّبِيُّ ـ صلى الله عليه وسلم ـ ‏ "‏ ارْجِعْ فَأَحْسِنْ وُضُوءَكَ ‏"‏ ‏.‏
Grade: Sahih (Darussalam)
Reference : Sunan Ibn Majah 665
In-book reference : Book 1, Hadith 399
English translation : Vol. 1, Book 1, Hadith 665