What was the relationship between the Jewish people and the Keinites?
Family ties
The Keinites were part of the Jewish nation – R"E HaModai in Mekhilta DeRabbi Yishmael Yitro Amalek 2, Targum Pseudo-Jonathan 18:27, Rashi 18:27, רמב"ןשמות י"ח:א'אודות ר' משה בן נחמן