Is the Hadith: "Indeed, whoever shuns his brother for more than three [days] and dies upon that enters the Hellfire" authentic, and what is its explanation?

Abandoning and quarreling for more than three nights is a grave and severe matter. Whoever dies insisting on it has merited entry into Hellfire, except that it is by the will of Allah; if He wills, He punishes him, and if He wills, He forgives him. As for whoever deems that permissible while knowing its prohibition, this is apostasy from the religion of Allah.