moral principle
彜 centers on a moral principle or constant standard of conduct. The meaning is narrow and abstract, referring to an enduring ethical rule.
The exact historical development of 彜 is uncertain. It may be related to ritual vessels or constancy, but the component origins are not clearly established.
The top 彑 looks like a hand holding something steady. Imagine a hand upholding an unchanging moral rule, like a constant principle.
For イ, picture an easel (イーゼル) holding a plaque with a moral principle written on it. The easel cues イ and the plaque represents the constant rule.