וַיֹּ֣אמֶר שָׁא֣וּל אֶֽל־הַקֵּינִ֡י לְכוּ֩ סֻּ֨רוּ רְד֜וּ מִתּ֣וֹךְ עֲמָלֵקִ֗י פֶּן־אֹֽסִפְךָ֙ עִמּ֔וֹ וְאַתָּ֞ה עָשִׂ֤יתָה חֶ֙סֶד֙ עִם־כָּל־בְּנֵ֣י יִשְׂרָאֵ֔ל בַּעֲלוֹתָ֖ם מִמִּצְרָ֑יִם וַיָּ֥סַר קֵינִ֖י מִתּ֥וֹךְ עֲמָלֵֽק׃
Saul berkata kepada orang Keni, “Pergilah, menyingkirlah, turunlah dari tengah-tengah orang Amalek, supaya aku tidak membinasakan kamu bersama mereka, sebab kamu telah menunjukkan kebaikan kepada seluruh bani Israel ketika mereka keluar dari Mesir.” Maka orang Keni pun menyingkir dari tengah-tengah orang Amalek.
Rashi
To the Kenites. Who were Yisro's descendants,9See Shoftim 1:16. who were residing in the wilderness of Yehudah, in the south of Arod, who went to Ya'aveitz to learn Torah, Arod being Amoleik. The Canaanite king of Arod was Amoleik, for it is stated [about him]; "who lived in the South,"10Bamidbar 21:1. and, "Amoleik dwells in the southern part of the land."11Ibid., 13:29.
Rashi
To all the Bnei Yisroel. Who partook from his [Yisro's] meal, Moshe, Aharon and all the elders of Yisroel.12See Shemos 18:12. It is considered as though he acted kindly with all the Bnei Yisroel.13It may also refer to Yisro’s hospitality of welcoming Moshe into his home when he escaped from Paroh [Shemos 2:20-21]. Based on this event R. Nechemyah in Maseches Berachos 63b states ‘how great is the reward for one who invites a Torah scholar into his house, gives him to eat and drink, and shares his possessions with him.’ Others believe that the act of kindness with all the Bnei Yisroel refers to the good advice that Yisro gave to Moshe with regard to setting up a system of judges [Shemos 18:14-26], because this benefitted the entire nation.
Tze'enah Ure'enah
“Saul said to the Kenites” [15:6]. Saul said to the Kenites. They were the descendants of Jethro, the father-in-law of Moses. Jethro had given good advice to Moses about how he should dispense justice to Israel.8Rashi, I Samuel, 15:6. Because of that advice Saul said: we will repay his descendants with good. We will tell them to leave Amalek in the expectation that they should not be killed among the Amalekites. From here we learn how the Holy One gives a good reward when someone gives good advice to his friend; his descendants are benefitted.