Pelusium
PELUSIUM pĭ lōō’ shĭ əm (Πηλούσιον, meaning uncertain; סִ֖ין) KJV SIN. A city at the NE extremity of the Nile Delta, about one m. from the Mediterranean.
The name means “city of mud” in Gr. This is evidently the result of false etymology. The Egyp. name Sin was confused with sin, “mud.” Though noted in antiquity for its flax and wine, the city acquired military importance as a frontier fortress facing Syria. Ezekiel (30:15) called it the “stronghold of Egypt.” It was the site of numerous battles. In 525 b.c. Cambyses defeated the Egyptians nearby and made Egypt a Pers. province. In 343 it was held by Artaxerxes and in 333 by Alexander the Great. In 169 it was seized by Antiochus IV. In 55, Gabinius and M. Antonius seized it for the Romans. In his campaign against Antonius the young Octavian occupied it in 30. During the Rom. empire the city was an important station on route to the Red Sea.
Additional resources
A city of Egypt mentioned only in Eze 30:15,16. This seems to be a pure Semitic name. The ancient Egyptian name, if the place ever had one such, is unknown. Pelusium (Greek Pelousion) also meant "the clayey or muddy town." The Pelusiac mouth of the Nile was "the muddy mouth," and the modern Arabic name of this mouth has the same significance. These facts make it practically certain that the Vulgate (Jerome’s Latin Bible, 390-405 A.D.) is correct in identifying Sin with Pelusium. But although Pelusium appears very frequently in ancient history, its exact location is still not entirely certain. The list of cities mentioned in Eze in connection with Sin furnishes no clue to its location. From other historical notices it seems to have been a frontier city. Rameses II built a wall from Sin to Heliopolis, probably by the aid of Hebrew slaves (Diodorus Siculus; compare Budge, History of Egypt, V, 90), to protect the eastern frontier. Sin was a meeting-place of Egypt with her enemies who came to attack her, many great battles being fought at or near this place. Sennacherib and Cambyses both fought Egypt near Pelusium (Herodotus ii.141; iii.10-13). Antiochus IV defeated the Egyptians here (Budge, VIII, 25), and the Romans under Gabinius defeated the Egyptians in the same neighborhood. Pelusium was also accessible from the sea, or was very near a seaport, for Pompey after the disaster at Pharsalia fled into Egypt, sailing for Pelusium. These historical notices of Pelusium make its usual identification with the ruins near el-Kantara, a station on the Suez Canal 29 miles South of Port Said, most probable. "Sin, the stronghold of Egypt," in the words of Ezekiel (30:15), would thus refer to its inaccessibility because of swamps which served as impassable moats. The wall on the South and the sea on the North also protected it on either flank.
Source 2
SIN (Heb. sîn, clay). An Egyptian city mentioned only in the KJV of Ezek.30.15-Ezek.30.16, called by the Greeks “Pelusium” (so niv), lying on the eastern arm of the Nile River. Ezekiel refers to it as “the stronghold of Egypt” (Ezek.30.15). A wall was built on the south, and with the sea on the north and impassable swamps on the other sides, the city was practically impregnable. Since Thebes and Sin were at the opposite ends of Egypt, mentioning these two cities as Ezekiel does implies God’s judgment falling on the entire land of Egypt.