Mordechai rectifies King Shaul's sin

בן קיש.

"Son of Kish" (Esther 2:5).

The Sefas Emes examines why Mordechai's lineage is traced to Kish.

ואיתא בתרגום שני שהי' מזרע שאול א"כ למה לא יחסו אחר המלך שאול.

And it is brought in Targum Sheni that he was of the seed of Shaul; if so, why was he not traced after King Shaul?

Since Mordechai descended from King Shaul, it is puzzling that the megillah names Kish rather than the more illustrious Shaul.

ומה"ט נד האבן עזרא מדברי חכמים.

And for this reason the Ibn Ezra departed from the words of Chazal.

This difficulty led the Ibn Ezra to part with the Sages' tradition on the matter.

אבל נראה שע"י ששאול חטא והשאיר מזרע עמלק לכן לא נזכר שמו בכאן.

But it appears that because Shaul sinned and left over from the seed of Amalek, therefore his name is not mentioned here.

The Sefas Emes resolves it: since Shaul's sin was sparing Agag and thereby leaving Amalek's line — the very source of Haman — his name is omitted in this context, where that unfinished business is being set right.

[אח"כ מצאתי בפי' הר"ש אלקבץ זצ"ל שכתב שתיקן חטא שאול.

[Afterward I found in the commentary of Rabbi Shlomo Alkabetz, of blessed memory, that he wrote that Mordechai rectified the sin of Shaul.

He later found support in the Manos HaLevi of R' Shlomo Alkabetz: Mordechai's role was to repair Shaul's failure with Amalek.

ונק' בן קיש שמילא מקום שאול בן קיש ע"ש.

And he is called "son of Kish" because he filled the place of Shaul son of Kish — see there.

Mordechai bears the title "ben Kish" because he stepped into the role of Shaul ben Kish, completing what Shaul left undone.

נראה כוונתו שבן קיש קאי על מרדכי הקודם.

It appears his intent is that "son of Kish" refers to Mordechai himself, mentioned earlier.

The Sefas Emes reads Alkabetz as applying "ben Kish" directly to Mordechai, not merely as distant genealogy.

ולפי זה נראה שיש בו סוד גילגול ועיבור נשמת שאול כנ"ל]:

And according to this it appears that there is in him a secret of gilgul (reincarnation) and ibbur (a soul-impregnation) of the soul of Shaul, as above.]

This implies a deeper sod: Mordechai carried the neshamah of Shaul, by way of gilgul or ibbur, in order to finish rectifying the sin against Amalek.

Summary: Mordechai is called "ben Kish" rather than traced to the famous King Shaul because Shaul sinned by sparing Amalek and leaving the seed from which Haman arose. Drawing on R' Shlomo Alkabetz, the Sefas Emes explains that Mordechai "filled the place" of Shaul ben Kish and rectified that sin — hinting at a deeper secret that Shaul's soul was reincarnated or impregnated within Mordechai to complete the unfinished war with Amalek.