Tonbokiri wants to warn him that sweeping quickly just spreads the dust everywhere-- but he seems to be doing all right.

Although feeling a little badly for reprimanding Izuminokami like this, he trusts that the sword will find a balance between the pride of a warrior and the humbleness of service in time.

But that will take time. Now, Tonbokiri lets him work on in silence, trusting that Izuminokami will feel better once he accomplishes the task set before him. Tonbokiri also resumes sweeping, although his pace is slow. Part of that is just how he is, but part of it is because he doesn't want to get in Izuminokami's way.