From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Shihor in   Isaiah 23:3 ,   Jeremiah 2:18 seems to mean Egypt (?), the Nile (?), or the waters of Egypt: in   1 Chronicles 13:5 ,   Joshua 13:3 , it is the S. W. frontier of Canaan. If the name is Hebrew it may mean ‘the Black,’ in allusion to the dark waters or even to the black alluvial land itself: the Egyp. name of Egypt is Kemi , meaning ‘black.’ But, as Brugsch pointed out, Shi-Hôr is the Egyp. name of a stream or canal, possibly the Pelusiac branch of the Nile, on or near the eastern border of Egypt (see Shur). The black alluvium might well be counted as the boundary of Canaan: but elsewhere the boundary is the ‘Brook’ (or ‘River’) of Egypt, i.e. the Wady el-Arish (see Shur).

F. Ll. Griffith.

Holman Bible Dictionary [2]

 Joshua 13:3 1 Chronicles 13:5 Isaiah 23:3 Jeremiah 2:18Brook Of EgyptPalestine Joshua 13:1

Easton's Bible Dictionary [3]

 1 Chronicles 13:5

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [4]

(Heb. Shichor', שַׁיחוֹר , [thus only in  Joshua 13:2-3;  1 Chronicles 13:5], or שַׁיהר [ Jeremiah 2:18], or שׁחֹר [ Isaiah 23:3], Dark ; once with the art. הִשּׁיחוֹר ,  Joshua 13:3, and once with the addition "of Egypt,"  1 Chronicles 13:5; Sept. Γη Ων , Αἰοίκητος , Ὅρια , and Μεταβολή ; Vulg. Sihior, Nilus, Fluvius Turbidus, and Aqua Turbida ; A.V. "Sihor" in all passages except  1 Chronicles 13:5), one of the names given to the river Nile, probably arising from its turbid waters, like the Greek Μέλας (Gesen. Thesaurus, s.v.). Several other names of the Nile maybe compared. Νε Ιλος itself, if it be as is generally supposed, of Iranian origin, signifies "the blue," that is, "the dark" rather than the turbid; for we must then compare the Sanscrit Nilah "blue, " probably especially "dark blue, " also even "black, " as "black mud." The Arabic azrak, "blue," signifies "dark" in the name Bahr el-Azrak, or Blue River, applied to the eastern of the two great confluents of the Nile. Still nearer, is the Latin Melo, from Μέλας , a name of the Nile, according to Festus and Servius ( Ad Virg. Georg. 4, 29, 1; Aen. 1, 745; 4, 246); but little stress can be laid upon such a word resting on no better authority. With the classical writers it is the soil of Egypt that is black rather than its river. So, too, in hieroglyphics, the name of the country, Kem, means "the black;" but there is no name of the Nile of like signification. In the ancient painted sculptures, however, the figure of the Nile god is colored differently according as it represents the river during the time of the inundation, and during the rest of the year; in the former case red, in the latter blue. (See Nile).

There are but three ocurrences of Shihor unqualified in the Bible, and but one of Shihor of Egypt, or Shihormizraim. In  1 Chronicles 13:5 it is mentioned, as the southern boundary of David's kingdom: "David gathered all Israel, from Shihor of Egypt even unto the entering of Hamath." At this period the kingdom of Israel was at the highest pitch of its prosperity. David's rule extended over a wider space than that of any other monarch who ever sat upon the throne; and, probably, as an evidence of this fact, and as a recognition of the fulfilment of the divine promise to Abraham ( Genesis 15:18) "Unto thy seed have I given this land, From The River Of Egypt unto the great river, the river Euphrates" the sacred historian may here have meant the Nile. Yet, in other places, where the northern boundary is limited to the "entrance of Hamath," the southern is usually "the torrent of Egypt," that is, Wady ( נחל , not נהר ) el-Arish ( Numbers 34:5;  1 Kings 8:65). There is no other evidence that the Israelites ever spread westward beyond Gaza. It may seem strange that the actual territory dwelt in by them in David's time should thus appear to be spoken of as extending as far as the easternmost branch of the Nile; but it must be remembered that more than one tribe, at a later period, had spread beyond even its first boundaries, and also that the limits may be those of David's dominion rather than of the land actually fully inhabited by the Israelites.

The passage in  Joshua 13:3 is even more obscure. The sacred writer is describing the territory still remaining to be conquered at the close of his life, and when about to allot the conquered portion to the tribes. "This is the land that yet remaineth all the borders of the Philistines and all Geshuri. from Shihor which is before ( עלאּפני , in the face of, not east of, but rather on the front of) Egypt, even unto the borders, of Ekron northward." Keil argues that Wady el-Arish, and not the Nile, must here be meant (Comment. ad loc.); but his arguments are not conclusive. Joshua may have had the Lord's covenant promise to Abraham in view; if so, Shihor means the Nile; but, on the other hand, if he had the boundaries of the land as. described by Moses in  Numbers 33:5 sq. in view, then Shihor must mean Wady el-Arish. It is worthy of note that, while in all the other passages in which this word is used it is anarthrous, here it has the article. This does not seem to indicate any specific meaning; for it can scarcely be doubted that here and in  1 Chronicles 13:5 the word is employed in the same sense. The use of the article indicates that the word is, or has been, an appellative rather the former if we judge only from the complete phrase. It must also be remembered that Shihor-mizraim is used interchangeably with Nahal-mizraim, and that the name Shihor-libnath, in the north of Palestine, unless derived from the Egyptians or the Phoenician colonists of Egypt, on account of the connection of that country with the ancient manufacture of glass, shows that the word Shihor is not restricted to a great river. That the stream intended by Shihor unqualified, was a navigable river is evident from a passage in Isaiah, where it is said of Tyre, "And by great waters, the sowing of Shihor, the harvest of the river (Yeor, יַאר ) [is] her revenue" ( 1 Chronicles 23:3).

Here Shihor is either the same as, or compared with, Yeor, generally thought to be the Nile. In Jeremiah the identity of Shihor with the Nile seems distinctly stated where it is said of Israel, "And now what hast thou to do in the way of Egypt to drink the waters of Shihor? or what hast thou to do in the way of Assyria to drink the waters of the river?" i.e. Euaphrates ( Jeremiah 2:18). Gesenius (ut sup.) considers that Sihor, wherever used, means the Nile; and upon a careful consideration of the several passages, and of the etymology of the word, we are of the opinion that it cannot appropriately be applied to Wady el- Arish, and must therefore be regarded as a name of the river Nile (see Jerome, Ad  Isaiah 23:3; Reland, Paloest. p. 286). (See River Of Egypt).

International Standard Bible Encyclopedia [5]

shı̄´hôr ( שׁיחור , shı̄ḥōr , also written without a yodh י and waw ו in Hebrew and incorrectly "Sihor" in English): A stream of water mentioned in connection with Egypt. Joshua (  Joshua 13:3 ) speaks of the "Shihor, which is before Egypt," a stream which commentators have thought to be "the brook of Egypt," the stream which separated Egypt from Palestine, now called Wâdy el - ‛Arish . Jeremiah ( Jeremiah 2:18 the King James Version) says, "What hast thou to do in the way to Egypt, to drink the waters of Sihor?" Commentators have thought Shihor in this case to be a name for the Nile. Both interpretations cannot be correct. Whatever the name South means, at least it did not denote a movable river. It must be the same stream in both these passages, and no identification of the stream can be correct that does not satisfy both of them. Professor Naville has recently shown conclusively ( Proc. Soc. Biblical Arch. , January, 1913) that neither of these interpretations is strictly correct, and has made clear the Biblical references to South. In the northeasternmost province of ancient Egypt, Khentabt ("Fronting on the East"), was a canal, a fresh-water stream drawn off from the Nile, called in the Egyptian language Shi - t - Hor , i.e. "the Horus Canal" (the - t - is an Egyptian feminine ending). There have been many changes in the branches and canals from the Nile in the Delta, and this one with many others has been lost altogether; but there is a tradition among the Bedouin of Wâdy el - ‛Arish to this day that once a branch of the Nile came over to that point. This Shi - t - Hor , "Stream of Horus," makes perfectly clear and harmonious the different references of Scripture to South. It was "before Egypt," as Josh describes it, and it was the first sweet water of Egypt which the traveler from Palestine in those days was able to obtain, as the words of Jeremiah indicate. "To drink the waters of South" meant to reach the supply of the fresh water of the Nile at the border of the desert. The two other references to South ( 1 Chronicles 13:5;  Isaiah 23:3 ) are perfectly satisfied by this identification. The "seed of South" ( Isaiah 23:3 the King James Version) would be grain from Egypt by way of the Shihor.