Which case specifically illustrates the transitional mukhāḍram generation rather than a Companion?

Companions, Successors, Mukhāḍramūn, and Attribution of Reports

• A later scholar who met a Companion
• A Muslim who lived for years with the Prophet
• Someone who lived in pre-Islamic times, embraced Islam during the Prophetic era, but did not meet him
• A Companion quoting a Successor’s saying