From Sahih Bukhari (Hadith 6653):
Narrated Abu Hurairah that he heard the Prophet (ﷺ) saying, "Allah decided to test three people from Bani Isra'il. So, He sent an angel who came first to the leper and said, '(I am a traveller) who has run short of all means of living, and I have nobody to help me except Allah, and then with your help.'" Abu Hurairah then mentioned the complete narration
Reference: Bukhari 6653