שמואל א ה׳:ט׳-י״ב

וישתרו. כמו ויסתרו, שהרי הוא במסורת כתובים שי"ן, ומפורשים בלשון סמ"ך, מכת בית הסתרים:

And they were afflicted internally.וַיִשָֹּתְרוּ is identical with וַיִסָּתְרוּ for it is listed in the Masora among those words written with a 'שֹ' and explained as though it were written with a 'ס' meaning "there was a plague in the hidden parts of the body."²Or it may mean that the plague occurred at night when it was dark and they were unable to see the שְׁרָצִים, i.e., the plague was hidden from them.—Da’as Sofrim

מהומת מות. כל מהומות על ידי רעם, וזה אביהן, (לקמן ז י): וירעם ה' בקול גדול (ביום ההוא) על פלשתים ויהומם, כך מפורש באגדת 'שלשים ושתים מדות' דרבי אליעזר בנו של רבי יוסי הגלילי:

Deadly upheaval. All upheavals [mentioned in Scripture] are caused by thunder. The following is the origin: "Adonoy thundered with a great noise on that day against the Philistines, making them panic.³Below 7:10. It is so explained in the Aggadah of Thirty-Two Rules of R. Eliezer, the son of R. Yose Haglili.