@msj121 which is the "one time"? If you are nervous discussing this further then no need. I am just curious. I have learned this maamar, and with my own baal chassidus Rav, not sure what you mean he mentions "above atzmuto umahuto Our Ein Sof"?
Fwiw his chassidim were well aware of how serious the topic of Atzmus is, and wouldn't just randomly make a wrong word around it, and I'm sure when the Rebbe said it, it was unforgettable
But I don't know what you mean this "one time" he mentions it? Which one time, can you cite it for me?