In Act IV, scene vii, when Claudius changes the sincerety of Laertes' grief, where does Laertes say he would be willing to cut Hamlet's throat?In what building?
Laertes says he would be willing to cut Hamlet's throat in the church. This is a shocking thing to say - Bloodshed in a holy sanctuary was forbidden, and so we recognize the depth of grief Laertes has gone to over the deaths of his father and sister, which he blames on Hamlet.
Claudius: "...what would you undertake, to show yourself your father's son in deed more than in words?
Laertes: To cut his throat i' the church." (Act IV, scene vii)