Where does “niergent” come from?

niergent (Middle High German) comes from Middle High German ne, from Old High German ne, from Proto-Germanic nē, from Proto-Germanic aiwaz, from Proto-Indo-European h₂eyu-, from Proto-Indo-European h₂ey- — vital force, life, age, eternity; day, morning.

Ancestry of “niergent”, step by step

Step	Language	Word	Meaning
1	Middle High German	ne	—
2	Old High German	ne	not
3	Proto-Germanic	nē	not
4	Proto-Germanic	aiwaz	long time, age, eternity
5	Proto-Indo-European	h₂eyu-	vitality; eternal; vital force, life, long life,...
6	Proto-Indo-European	h₂ey-	vital force, life, age, eternity; day, morning

Every word from Proto-Indo-European h₂ey- →Every word from Proto-Indo-European h₂eyu- →Every word from Proto-Germanic aiwaz →