। ॥ ४२१ ॥
In plain words
If the next stage never comes, everything before it was wasted — each step only matters because it leads to the one after. And when that final letting-go does arrive, it is complete fulfillment: a joy with nothing to compare it to, needing nothing outside itself to be what it is.
Close to the Sanskrit
If each successive [stage] fails to occur, each preceding one is fruitless. Cessation [the final withdrawal] is the supreme satisfaction; bliss is incomparable, self-existent.