thumb|300x300px|The Besor stream () and nearby streams, with the Bronze and Early Iron Age sites and modern towns of the area.
The Brook of Egypt () is a wadi identified in the Hebrew Bible as forming the southernmost border of the Land of Israel. A number of scholars have identified it with Wadi al-Arish, an ephemeral river flowing into the Mediterranean sea near the Egyptian city of Arish, while Israeli archaeologist Nadav Na'aman believes that the landform referenced in the Bible is the Besor Stream, just to the south of Gaza.
The Septuagint translates Naḥal Mizraim in Isaiah as Rhinocorura.
Although in later Hebrew the term naḥal tended to be used for small rivers, in Biblical Hebrew, the word could be used for any wadi or river valley.
According to Sara Japhet, "Nahal Mizraim" is Wadi al-Arish, which empties into the Mediterranean Sea about 30 miles south of Raphia, and "Shihor Mizraim" is the Nile.
Nahal Besor
The Israeli archaeologist Nadav Na'aman has suggested in papers published in 1979 and 1995 that Wadi Gaza, or Nahal Besor, is the Brook of Egypt. Certainly, it was controlled by Egypt in the Late Bronze Age and inhabited by Philistines into the Iron Age. In the 1995 paper Na'aman cites evidence that "the area of Nahal Besor experienced an unprecedented demographic boom in the seventh century, whereas the area near Wadi el-'Arish was sparsely inhabited at that time", It also appears in medieval commentaries by Rashi and David Kimhi on Joshua 13:3. However, most historical commentators, such as Abraham Ibn Ezra, Bahya ben Asher, Samuel David Luzzatto, Naftali Zvi Yehuda Berlin, Moisè Tedeschi on Numbers 34:5, and the translators of the Targum Onkelos reject this interpretation, as do modern scholars.