'Man' in the Bible

For neither did I receive it from man, nor was I taught [it], but [I received it] through a revelation of Jesus Christ.

Brothers, I am speaking according to a human perspective. Nevertheless, [when] the covenant of a man has been ratified, no one declares [it] invalid or adds additional provisions [to it].

And again I testify to every man who becomes circumcised, that he is under obligation to keep the whole law.