Is true that Allah swt created the nur (light) of Ahlul Bayt (as) before anything and from that light created all that is good ? If it is what are the sources (ahadith) for it ?

We do have those generations and there are authentic ones that both Shia and Sunni narrate in which we are told the first was the light of the holy prophet peace be upon him and his progeny.

This type off narration needs explanation and are difficult to understand because it is speaking of a realm beyond our physical world