Sahl bin Saad reported,

He heard the Prophet ﷺ say on the day of Khaybar, "I shall give the banner to a man through whose hands Allah will grant victory."The men spent the night wondering which of them would be given it, and in the morning they all came hoping to receive it.The Prophet ﷺ asked, "Where is Ali?"He was told, "He is suffering from his eyes."So he ordered that Ali be brought to him, and when he came, he spat into his eyes, and Ali was healed on the spot as though nothing had ever ailed him.Ali asked, "Shall we fight them until they become like us?"The Prophet ﷺ replied, "Proceed calmly until you reach their territory, then call them to Islam and inform them of what is required of them. By Allah, for Allah to guide a single man through you is better for you than red camels."

Bukhari 2942

Sahih

حدثنا عبد الله بن مسلمة القعنبي حدثنا عبد العزيز بن أبي حازم عن أبيه

عن سهل بن سعد رضي الله عنه

سمع النبي ﷺ يقول يوم خيبر لأعطين الراية رجلا يفتح الله على يديه فقاموا يرجون لذلك أيهم يعطى فغدوا وكلهم يرجو أن يعطى فقال أين علي فقيل يشتكي عينيه فأمر فدعي له فبصق في عينيه فبرأ مكانه حتى كأنه لم يكن به شيء فقال نقاتلهم حتى يكونوا مثلنا فقال على رسلك حتى تنزل بساحتهم ثم ادعهم إلى الإسلام وأخبرهم بما يجب عليهم فوالله لأن يهدى بك رجل واحد خير لك من حمر النعم

البخاري 2942صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Jihad and expeditions
Chapter
Invitation of the Prophet ﷺ to Islam and prophethood, and that none should take others as lords besides Allah
Numbering
Darussalam 2942
Bukhari 2942