Adam Clarke on John 7:29

But I know him: for I am from him - Instead of εἰμὶ, I am, some editions, the Syriac Hieros. read εἷμι, I came, according to the Attics. Nonnus confirms this reading by paraphrasing the word by εληλυθα, I came. As the difference between the two words lies only in the accents, and as these are not found in ancient MSS., it is uncertain which way the word was understood by them: nor is the matter of much moment; both words amount nearly to the same meaning and εἷμι, I came, seems too refined.