touch         neck           without       way 
The gods said, "Brok's things are the best."
Brok gave the hammer to Thor. That is the way Thor got his wonderful hammer.
Then Brok said to Loki, "You said I could have your head if my things were the best."
And Loki was angry and said, "Yes, I told you that you could have my head. But you can't touch my neck."
Of course, Brok could not get his head without touching his neck.
So Brok did not get Loki's head.