Jesus and the rich man

You are correct: Jesus never sinned during his earthly life (2 Corinthians 5:21; Hebrews 4:15; 1 Peter 1:19). Jesus was perfect in our place.

I am not sure which Bible reference you have in mind with your question. I am wondering if it could be Jesus’ conversation with the rich man in Mark 10:17-22. In that conversation, Jesus told the man, “No one is good—except God alone” (Mark 10:18).

Jesus was restating the truth of Psalm 14:2-3 and Psalm 53:2-3: all people are sinners. The only one who is good—in every sense of the word—is God. As Jesus is God, his words to the rich man pointed to himself as God and Savior.

I hope I have come close to answering your question.