For one whose thirst is exhausted, all suffering ceases. The elder, without stain, dwells in joy, investigating with discernment.

Vīta-taṇhassa — one whose thirst is exhausted, gone. Not satisfied, but exhausted. The water is still there, but you no longer have thirst.

Nikkhilo — without stain. The elder (thero) represents the maturity of the path. Joy (pāmojja) is not excitement, it is the serenity of one who no longer seeks.