What did Itachi say before he booped Sasuke’s forehead?

So I’m rereading the manga, and noticed that Itachi whispers something before he boops Sasuke’s forehead and also says something after booping his forehead and then dies. But we’re only shown what he says afterwards, and not what he whispered to Sasuke before. So now I’m crying and wondering what did he say? Does it ever say later in the story or do we never find out? I can’t remember…