“So the Pharisees said to him, “You are bearing witness about yourself; your testimony is not true.” Jesus answered, “Even if I do bear witness about myself, my testimony is true, for I know where I came from and where I am going, but you do not know where I come from or where I am going.” (John 8:13–14, ESV)
Are the Pharisees correct when they call a technical foul on Jesus because he is bearing witness about himself? No. They are wrong, says Jesus.
Why? I’m glad you did
A. T. Robertson references Stier in his fantastic book Word Pictures in the New Testament:
“Stier (Words of the Lord Jesus) argues that one might as well say to the sun, if claiming to be the sun, that it was night, because it bore witness of itself. The answer is the shining of the sun.”
And that, dear reader, answers that particular objection.