Could you please paraphrase the following sentences?

"satan was not omniscient, but... it was as if the evil one had picked up some hint in the heavenlies, some whispered suggestion of how God might use the two of them together."
(This is about the same awful experience which both Joni and Ken had at the same time, but in different places.)
Thanks.
From:
Joni and Ken: An Untold Love Story
by Ken Tada (Author), Joni Eareckson Tada (Author), Larry Libby (Contributor)
chapter seven