who gave him [Sayoc] the idea...who put him up to it. Who planted the motive.

Easy! Trump & his violence-supporting Republican/Trumpist enablers & supporters.

who taught Cesar Seyoc to make bombs.

Any one of dozens- if not hundreds- of websites. The information is freely available. Another benefit of the Internet.

The truck driver who attacked Jews in Pittsburgh told police that Jews are committing genocide against his people. Who gave him that idea?

Well, Trump himself to begin with, or his officials/buddies Steve Bannon, Sebastian Gorka, Doug Domenech, Jon Feere, Julie Kirchner,Teresa Manning, Shannon Royce, Charmaine Yoest, or from any of Trump's "Very Fine Nazis" in Charlottesville & elsewhere and from their numerous anti semitic and/or white supremecist websites, from Brietbart, from Qanon- the sources are endless - and the vast majority of them inspired and energized by or approved of by Trump.

Does that help?