The perfection of His beauty was such that even those companions who used to be present in His presence day and night could not bear an eyeful of it.
There is a Hadith in Sahih Muslim:
Translation: Hadhrat ‘Amr bin A’as (May Allah be well pleased with him) says, “Nobody is dearer to me than the Holy Prophet (Sallallahu alaihi wa sallam); and nobody, in my opinion, is more noble and honorable than Him; because of the Holy Prophet’s (Sallallahu alaihi wa sallam) grandeur and magnificence, I could never take a good look at Him. If anyone asks me about His personality, I cannot describe it as I could never take a good look at Him.”- Sahih Muslim, Vol 1, Pg no. 76.
Hadhrat Bara bin A’azib (May Allah be well pleased with him), says:
Translation: “With respect to His face and His person, the Holy Prophet (Sallallahu alaihi wa sallam) is the best among all people. (Sahih Bukhari- Vol 1, Pg No: 502)