Bible Gateway:
https://www.biblegateway.com/passage/?search=Mark+9&version=AMP
Bible Hub Commentary Mark 9:35
https://biblehub.com/commentaries/mark/9-35.htm
Matthew Henry's Concise Commentary:
Many remain ignorant because they are ASHAMED to INQUIRE.
Alas! that while the Saviour TEACHES so PLAINLY the things which belong to His Love and Grace, people are so blinded that they
DON’T UNDERSTAND His sayings.

From T.H.M.: Simply put we say to our self, “It can’t possibly be that simple, the true meaning must be hidden somewhere”.
SPIRITUAL WISDOM
…15The SPIRITUAL PERSON judges all things, but they themselves are not subject to ANYONE’S JUDGMENT. 16“For who has known the mind of the Lord, so as to instruct Him?”
But We Have The Mind Of Christ. 1 Corinthians 2:15-16