In its original meaning, "器" referred to specific wares/instruments, each with a specific application, such as cutlery or utensils. However, a device is frequently restricted to a single usage and cannot be combined.

A gentleman shouldn’t be like a piece of kitchenware with only one use and a single purpose, which means he shouldn’t stick to the means without thinking about the purpose behind it.

“器”的本意指器具或者器皿，指某种工具，各有其用。 但一种器具往往只限于一定的功能而不能相通使用。

君子不能像器具那样，只具有一种功能、只限于一定的用途。
君子不应拘泥于手段而不思考其背后的目的。