What did Hashem inform Yirmeyah?
Rashi: Their punishments.
Radak citing his father: That they were plotting to feed him poison, like the coming verse says. Had He not told me, I would not have known. It would not have crossed my mind, for I did not harm them. If I rebuke them, it is for their good!
Malbim: At the same time that Hashem spoke bad about you, He informed me of the decree.
Why did he say "Az Hir'isani Ma'aleleihem"?
Radak: Through this (telling me that they want to poison me), Hashem showed me their evil deeds. If they wanted to do so to me, all the more so to others! Hodi'ani is third person, and it says Hir'isani (second person) in the same verse. There are many verses like this.
Malbim: At the same time that He informed me of the decree, He showed me their evil deeds, so I know that they deserve the punishment. I also saw what they want to do to me.
