yi, tripod, wine vessel, rule
彛 is a rare kanji with no clear standalone meaning in modern Japanese. Its given meanings point to an ancient Chinese ritual bronze tripod wine vessel, and by extension a rule or standard, but treat its meaning as uncertain.
彛 is a variant of 彝, which historically depicts a ritual bronze vessel with a bird or animal shape, often used for wine. The lower 廾 represents two hands holding the vessel. The exact historical development of this variant form is uncertain.
The bottom 廾 looks like two hands holding up an elaborate vessel. Picture a tripod wine container being offered with both hands, representing a ritual rule.
For イ, imagine an eagle (イーグル) perched on the tripod vessel: the 'イ' sound from eagle helps recall the reading.