《后汉书·列传·郎顗襄楷列传下》
臣听说布谷鸟在孟夏叫，蟋蟀在初秋叫，物虽微小而不失信，人有卑贱而言忠。
臣闻布谷鸣子孟夏，蟋蟀吟于始秋，物有微而志信，人有贱而言忠。
I heard that the cuckoo calls in early summer and crickets call in early autumn, despite their small size, they never fail to keep their words, even a humble person can be loyal.