This sentence mainly emphasizes the individual's inner self-completeness and the pursuit of independence from the outside world.
"Self-sufficiency" means that everyone has enough potential and ability within themselves to develop and realize their own value independently. This self-completeness is inherent in everyone and does not need to be obtained through external pursuits.
“Don’t seek externally” emphasizes not relying on external material, power or recognition from others to meet one’s needs. It reminds people to look for answers from within and explore their own potential and wisdom, rather than blindly pursuing external material wealth or social status.