וַיַּשְׁכִּ֣ימוּ בַבֹּ֔קֶר וְהַשֶּׁ֖מֶשׁ זָרְחָ֣ה עַל־הַמָּ֑יִם וַיִּרְא֨וּ מוֹאָ֥ב מִנֶּ֛גֶד אֶת־הַמַּ֖יִם אֲדֻמִּ֥ים כַּדָּֽם׃
Wstawszy jednak zrana nazajutrz, gdy słońce nad wodą zabłysło, ukazała się Moabitom woda zdaleka, czerwona niby krew.
Rashi
Red as blood. Such is the nature of water; when the sun shines on it in the morning, causes it to appear red.
Rashi
From a distance. At a distance, but because they had never seen water in that valley, they, therefore, thought that it was blood.