וַיַּהֲפֹ֣ךְ לְ֭דָם יְאֹרֵיהֶ֑ם וְ֝נֹזְלֵיהֶ֗ם בַּל־יִשְׁתָּיֽוּן׃
Dia mengubah sungai-sungai mereka menjadi darah, sehingga mereka tidak dapat meminum air dari aliran-aliran mereka.
Midrash Lekach Tov
Behold, with the rod that is in my hand, I will strike the water: The ten plagues were inscribed upon the staff of Moshe - Detsakh (the initials of the first three plagues), Adash (the initials of the second three plagues), Beachav (the initials of the last four plagues). Since they spilled the blood of the Jewish people like water, "He turned their rivers into blood; He made their waters undrinkable" (Psalms 78:44).