1)
Why will Chanam'el come to Yirmeyah?
1.
Rashi: Hashem will tell him to come.
2.
Radak (6-7): He needs to sell his field. Since you are the Go'el (if he sold it to someone else, you are commanded to buy it), it is proper that you buy it from him!
2)
Why did he say "Lecha Mishpat ha'Ge'ulah Liknos"?
1.
Radak: Refer to 32:7:1:2.
