"I believe paper or other easily combustible material would be helpful."

Daneel considers their options. There is, of course, the romance novel he has been reading, but that seems somewhat... wasteful. The book is not truly his to destroy, and may still contain useful information.

"I can perhaps fetch some of my drawing paper," he volunteers. "That will be effective for starting a fire. Unless, perhaps, you have something better in mind?"

Because he's unwilling to leave Ned alone even that long.