Y'know, over on Lemmygrad, a lib interloper asked if this was a legitimate quote from the man of steel himself and I had to dig up a Russian-language book (there is no english translation afaik) and to stumble my way through the cyrillic to find the source for this.
This quote is according to Molotov's recollection. From Сто сорок бесед с Молотовым (140 Conversations with Molotov) by Felix Chuev:
Stalin himself, I remember, said during the war: “I know that after my death, my grave will be piled with rubbish. But the winds of history will ruthlessly dispel it!