Where does “nursing” come from?

I can't write this sentence because the etymology chain provided contains only English forms repeating in a loop, with no older language sources identified. An etymology requires a chain extending into older languages (Old English, Middle English, Latin, etc.). The repetition suggests incomplete or corrupted data. To write an accurate one-sentence origin summary, I would need the chain to show progression into at least one language preceding Middle English.

nursing (English): In the state of suckling young, lactating;...