What did King Claudius letters say to hamlet?

In King Claudius's letters to Hamlet, he expresses concern for Hamlet's well-being and his grief over his father's death. Claudius invites Hamlet back to court, attempting to manipulate him into returning to Denmark, while also maintaining an appearance of benevolence. The letters serve as a strategic move to control Hamlet and manage the political situation, highlighting Claudius's duplicity and his desire to maintain power.