Khanti: Patient endurance
Khanti is forbearance under provocation, the strength to wait. Slow to anger reads here as a long fuse: the people have just wept all night, talked of stoning Moses, and set their faces back toward Egypt, and still the response takes its time. Patience of that sort leaves room for something other than punishment to happen next.
Mettā: Loving kindness
Mettā is goodwill that wishes beings well without conditions attached. Abundant in loving kindness is a well that does not run dry as the wrongs pile up, which is why Moses can draw on it even after the spies' report has poisoned the whole camp. Goodwill kept in that supply is what makes the pleading worth making.
Avera: Freedom from enmity
Avera is the absence of hostility toward anyone at all. Forgiving iniquity and disobedience sets the ledger of grievance down instead of carrying it forward another year. A grudge answered by a grudge feeds the fire, and the fire goes out only when one side stops adding wood; here the side with every reason to burn is the one that stops.
Kammavipāka: The ripening of deeds
Kammavipāka is the fruit a deed brings when it matures. Clearing the guilty is the one thing withheld even where pardon is freely given: the wrong is forgiven and the wrong still ripens, the way a seed already in the ground comes up whether or not the sower has cooled down. That generation is spared destruction and still dies in the wilderness.
Paṭicca-samuppāda: Dependent arising
Paṭicca-samuppāda is the principle that things come about through their conditions. Iniquity visiting the children to the third and fourth generation traces a chain of causes rather than a debt collector working down a family list: frightened parents raise frightened children, and a camp that refuses the land hands its refusal down like a family trade. Where the conditions stop, the effect stops with them, which is why the children raised in that wilderness are the ones who finally cross.