句子使用了'be strict with... and lenient with...'的并列结构，强调了两种对比态度带来的积极结果。
When making friends, be strict in conduct and faithful in keeping promises. — Confucius
The noble man thinks of virtue, while the petty man thinks of land. The noble man thinks of the law, while the petty man thinks of favors. — Confucius, The Analects
I am worried about: not cultivating one's virtue, not studying one's learning, not following the right when it is heard, and not correcting one's faults. — Confucius, The Analects
If you are strict with yourself and lenient with others, you will be far removed from resentment. — Confucius, The Analects
To love learning is near to wisdom; to act with determination is near to benevolence; to know shame is near to courage. — Confucius, The Doctrine of the Mean
The noble man schemes for the Way, not for food; he worries about the Way, not about poverty. — Confucius
The petty man is agreeable but not harmonious; the noble man is harmonious but not merely agreeable. — Confucius, The Analects, Book of Zi Lu
Climbing Mount Dong, Lu seems small; climbing Mount Tai, the world seems small. — Confucius
The benevolent man, wishing to be established, establishes others; wishing to be successful, helps others to be successful. — Confucius
Do not worry about having no position, worry about the ability to sustain a position. Do not worry about others not knowing you, strive to be worthy of being known. — Confucius, The Analects
与朋友交往，要严肃认真且讲究信用。——孔丘
君子惦记的是道德，小人惦记的是田宅；君子畏惧的是刑法，小人贪求的是恩惠。——孔子《论语》
品德不修养，学问不讲习，听到义理不能追随，不善不能改正，这是我担忧的事。——孔子《论语》
严格地要求自己，宽厚地对待别人，就可以避免别人的怨恨了。——孔丘《论语》
爱好学习就接近智，努力行动就接近仁，知道羞耻就接近勇。——孔子《中庸》
君子谋划的是道义，而不是衣食；忧虑的是道义能否实现，而不是贫穷。——孔丘
小人只是表面上附和，内心并不和谐；君子追求和谐，但不盲目苟同。——孔子《论语·子路》
登上东山，就觉得鲁国变小了；登上泰山，就觉得天下变小了。——孔丘
仁德的人，自己想成功也要帮助别人成功，自己想通达也要帮助别人通达。——孔子
不担心没有职位，只担心自己凭什么立身处世；不担心没有人了解自己，只求自己拥有值得被人了解的本领。——孔子《论语》