Language:
كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
(38)
Chapter: Ghazwa of Khaibar
(38)
باب غَزْوَةُ خَيْبَرَ
Sahih al-Bukhari 4206

Narrated Yazid bin Abi Ubaid:

I saw the trace of a wound in Salama's leg. I said to him, "O Abu Muslim! What is this wound?" He said, "This was inflicted on me on the day of Khaibar and the people said, 'Salama has been wounded.' Then I went to the Prophet (ﷺ) and he puffed his saliva in it (i.e. the wound) thrice., and since then I have not had any pain in it till this hour."

حَدَّثَنَا الْمَكِّيُّ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا يَزِيدُ بْنُ أَبِي عُبَيْدٍ، قَالَ رَأَيْتُ أَثَرَ ضَرْبَةٍ فِي سَاقِ سَلَمَةَ، فَقُلْتُ يَا أَبَا مُسْلِمٍ، مَا هَذِهِ الضَّرْبَةُ قَالَ هَذِهِ ضَرْبَةٌ أَصَابَتْنِي يَوْمَ خَيْبَرَ، فَقَالَ النَّاسُ أُصِيبَ سَلَمَةُ‏.‏ فَأَتَيْتُ النَّبِيَّ صلى الله عليه وسلم فَنَفَثَ فِيهِ ثَلاَثَ نَفَثَاتٍ، فَمَا اشْتَكَيْتُهَا حَتَّى السَّاعَةِ‏.‏
Reference : Sahih al-Bukhari 4206
In-book reference : Book 64, Hadith 246
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 517
  (deprecated numbering scheme)