[This person he was having a conversation with other than passing greeting words was asking him to hand over the sledgehammer. Mouri's first thought is a definite 'NO', why would you give Yato a weapon?

Then the rest of himself takes the decision]

Here you go. There's no way I would accept having one in my room for the moment.

[At least now he knows Yato has a sledgehammer. That is good for something, Mouri supposes. Mouri manages to pull the sledgehammer towards Yato, trying to give it to him]

You don't need to promise anything. At this point it's useless to believe anyone won't be tempted to kill.

[Back at home he had to accept that, too. Practically the only people he can't imagine ever killing is himself and his family. Everyone else in the world - or the multiverses - is fair game, as far as he is concerned]