Mark 10:44
And whosoever of you will be the chiefest, shall be servant of all.
Cross-reference
1 Kings 12:7
Parallel
1 Kings 12:7 advises a king to serve the people, providing an OT example of servant leadership.
Matthew 23:11
Parallel
Matthew 23:11 repeats the principle that the greatest must be servant, reinforcing the 'slave of all' command.
Philippians 2:7
Parallel
Philippians 2:7 describes Christ taking the form of a servant, providing the ultimate example of being a slave.