וַהֲדַ֞ד שָׁמַ֣ע בְּמִצְרַ֗יִם כִּֽי־שָׁכַ֤ב דָּוִד֙ עִם־אֲבֹתָ֔יו וְכִי־מֵ֖ת יוֹאָ֣ב שַֽׂר־הַצָּבָ֑א וַיֹּ֤אמֶר הֲדַד֙ אֶל־פַּרְעֹ֔ה שַׁלְּחֵ֖נִי וְאֵלֵ֥ךְ אֶל־אַרְצִֽי׃
און װי הַדַד האָט געהערט אין מצרים אַז דוד האָט זיך געלײגט מיט זײַנע עלטערן, און אַז יוֹאָבֿ דער חיל-פֿירער איז טױט, אַזױ האָט הַדַד געזאָגט צו פּרעהן: לאָז מיך אַװעק, און איך װעל גײן אין מײַן לאַנד.
Rashi
That Dovid slept. For Dovid who died of natural causes, an expression of sleeping [שכיבה] is mentioned; but for Yoav who was killed, an expression of dying [מיתה] is mentioned.. Another explanation is that concerning Dovid who was survived by a meritorious son who took his place, [an expression of] sleeping is mentioned, but concerning Yoav who was not survived by a meritorious son who took his place, [an expression of] sleeping is not mentioned, rather, [an expression of] dying [is mentioned].7Maseches Bava Basra 116a.