Definition
This idiom is used to emphasize that rules or standards should be applied equally to everyone; if something is acceptable for one person, it should also be acceptable for another in similar circumstances.
己所欲，亦勿施於人；一視同仁。
If the company allows John to work from home, then Mary should have the same right.
如果公司允許約翰在家工作，那麼瑪麗也應該有同樣的權利。
Since you let your son get away with breaking the rules on the playground, you should allow your daughter to do the same.
既然你讓你的兒子在遊樂場違反規則而不受懲罰，你也應該允許你的女兒這樣做。
If the team allows one member to be late, then others should also be allowed to be late, though this should not become a habit.
如果團隊允許一名成員遲到，那麼其他人也應該被允許遲到，儘管這不應該成為習慣。