This is an idiom. Literally, it means knocking pheasants to signal that one's troops are retreating and returning to camp to rest, which means that the war is temporarily over.
Pheasant is made of copper, and its shape is very similar to that of our common temple bell, but the top of pheasant will have a long handle, which is convenient to carry and hold in battle. But also can not be easily damaged, and the service life can be said to be quite long.
At the same time, there is another word called "drumming", which corresponds to "ringing gold". The only difference between the two is that one is to launch a charge and the other is to send a signal back to the city. As far as I know, pheasants can also restrain the army from marching. In a popular saying, when you need to retreat or stop, ring the bell to solve it.
This idiom comes from Xunzi? Discuss the soldiers, as written in the ancient book: drums advance, golden sounds retreat. "Ring the golden bell and leave" is also a comprehensive explanation of the second half sentence.
Moreover, it is said that the sound made by this instrument is very long, loud and shocking, and it can also spread to far places, which is also in line with the characteristics that all our own soldiers must be informed when they need to retreat on the battlefield. Just like the morning bell that rings regularly in a temple, even if it is not in the valley, it will have a loud echo.
However, there are no special restrictions on the size of pheasants, and it is best to customize them according to specific conditions. According to my inference, it is impossible for a pheasant to do exactly the same thing every time, so the sound it makes should be different, and there will always be some subtle differences. Otherwise, on the battlefield, soldiers can't recognize their retreat. What should they do?