וַיַּחְפְּר֧וּ כָל־מִצְרַ֛יִם סְבִיבֹ֥ת הַיְאֹ֖ר מַ֣יִם לִשְׁתּ֑וֹת כִּ֣י לֹ֤א יָֽכְלוּ֙ לִשְׁתֹּ֔ת מִמֵּימֵ֖י הַיְאֹֽר׃
И все египтяне рыли вокруг реки, чтобы пить воду; потому что они не могли пить из воды реки.
Sforno
ונלאו מצרים, digging around the river bed trying to find water. This referred to what the Torah described in verse 24 ויחפרו כל מצרים סביבות היאור, “all the Egyptians dug all around the river.”
Rashi
A worn-out garment on a cold day Heb. מעדה בגד, synonymous with (Isa. 64:5): “בגד עדים, a discarded garment,” a worn-out garment that is fit to be taken off since it is worn out, as we translate into Aramaic “ויסר” (Ex. 7:24) as ויעדי, and He shall remove. Now this is its interpretation: A worn-out garment on a cold day is like vinegar on chalk. chalk Heb. נתר, a kind of soft earth, like our earth that is called creide, which they would hew and make vessels therefrom, and if vinegar falls on it, [the earth] is dissolved and ruined. So... is one who sings songs to a broken heart [lit. on a bad heart. This one] resembles them both. Now what is one who sings songs? This is one who teaches the Torah to a wicked student, who has no intention in his heart to fulfill it.
Da'at Zekenim
ויעשו כן, “and the sorcerers of Pharaoh did something similar (with the aid of their witchcraft)” Where did they take water from to duplicate such a feat? Either they brought the water from outside Egypt, or they must have dug for it. Also, the fact that the Egyptians are reported to have dug for water, something reported in verse 24 also seems out of place. We do not apply the principle of the Torah reversing historical sequences within the same paragraph.