Source: Rabinical Literature: Or, The Traditions Of The Jews, Contained in Their Talmud and Other Mystical Writings Likewise the Opinions of that People Concerning Messiah, and the Time and Manner of His Appearing : With An Appendix, Comprizing Buxtorf’s Account of the Religious Customs and Ceremonies of that Nation ; Also, A Preliminary Enquiry Into the Origin, Progress, Authority, and Usefulness of These Traditions ; Wherein the Sense of the Strange Allegories in the Talmud and Jewish Authors is Explained ; In Two Volumes · Volume 2 (Bavarian State Library) 1748 A.D.
This source confirms that David the Reubenite was a black man. This source highlights the Sabbation River and Rabby Meir (the famous Rabbi Meir) who noted that a blackmoor had sand from the Sambation River.
and then