Hadithcore
Sahih al-Bukhari, 341
sahih

Narrated `Abdur Rahman bin Abza:

`Ammar said to `Umar "I rolled myself in the dust and came to the Prophet (ﷺ) who said, 'Passing dusted hands over the face and the backs of the hands is sufficient for you.' "

حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، أَخْبَرَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ ذَرٍّ، عَنِ ابْنِ عَبْدِ الرَّحْمَنِ بْنِ أَبْزَى، عَنْ عَبْدِ الرَّحْمَنِ، قَالَ قَالَ عَمَّارٌ لِعُمَرَ تَمَعَّكْتُ فَأَتَيْتُ النَّبِيَّ صلى الله عليه وسلم فَقَالَ ‏

‏ يَكْفِيكَ الْوَجْهُ وَالْكَفَّانِ ‏

‏‏.‏

References2 variants
In-Book Reference
Book 7, Hadith 8
USC-MSA web (English) reference
Vol. 1, Book 7, Hadith 337 (deprecated numbering scheme)