Those who can see clearly are tall people
Sima Yi said:
Looking at the shortness of people, there is no one in the world who can be handed over
Looking at the length of people, everything in the world is my teacher
Along the way, there are no enemies all friends and teachers!
What this probably means is:
Don't just look at other people's shortcomings, so that you can't make a friend.
Look at people to see the strengths of others, so that you see that everyone is your friend, and you can learn from others.
Sima Yi is a person with a deep understanding of the city government, and Sima Yi's principle of dealing with the world is that if he can't say it, he can't bear not to say it, and he can't see through it!
A lifetime of sharpening the sword, with the sword only used once is enough.