The Rabbis on the Samaritans. Sources:

 

On their ritual slaughter as kosher: Babylonian Talmud, Chullin 5b.

On their wine: Babylonian Talmud, Chullin 6a.

On their Passover matzoth:  Tosefta Pessachim 113; Jerusalem Talmud Avoda Zara V (44a) and Tractate Kuttim II2.

On a bill of divorce: Mishna, Gittin I 5

On grace at meals: Mishna, Berachot VII 1

On ritual purity: Dewarim rabba II 33