ISHMAELITE
(Ishʹma·el·ite) [Of (Belonging to) Ishmael].

A descendant of Ishmael, the firstborn son of Abraham by Hagar, the Egyptian handmaid of Sarah. (Ge 16:1-4, 11) Ishmael, in turn, married an Egyptian by whom he had 12 sons (Nebaioth, Kedar, Adbeel, Mibsam, Mishma, Dumah, Massa, Hadad, Tema, Jetur, Naphish, Kedemah), the chieftains of the various Ishmaelite clans. (Ge 21:21; 25:13-16) The Ishmaelites, therefore, were at the start one fourth Semitic and three fourths Hamitic, racially speaking.

As God had promised, the Ishmaelites grew to become “a great nation” that ‘could not be numbered for multitude.’ (Ge 17:20; 16:10) But instead of settling down (they built few cities), they preferred the nomadic life. Ishmael himself was “a zebra of a man,” that is, a restless wanderer who roamed the Wilderness of Paran and lived by his bow and arrows. His descendants were likewise tent-dwelling Bedouin for the most part, a people who ranged over the Sinai Peninsula from “in front of Egypt,” that is, to the E of Egypt and across northern Arabia as far as Assyria. They were noted for being a fierce, warlike people hard to get along with, even as it was said of their father Ishmael: “His hand will be against everyone, and the hand of everyone will be against him.”—Ge 16:12; 21:20, 21; 25:16, 18.

In further describing the Ishmaelites, it is said: “In front of all his brothers he settled down [Heb., na·phalʹ].” (Ge 25:18) Similarly, the Midianites and their allies, it was said, “were plumped [no·phelimʹ, a participle form of na·phalʹ] in the low plain” in Israelite territory until Gideon’s band forcefully routed them. (Jg 7:1, 12) Hence, when the Ishmaelites “settled down” it was evidently with the intent of holding on to the region until forcefully removed.

In the course of time it is quite likely that intermarriage between Ishmaelites and descendants of Abraham through Keturah (Ge 25:1-4) occurred, resulting in the inhabitants of sections of Arabia. Since Ishmael and Midian were half brothers, any intermarriage of their respective descendants with the amalgamation of their blood, habits, traits, and occupations could have given rise to an interchangeable usage of the terms “Ishmaelites” and “Midianites,” as is noted in the description of the caravan that sold Joseph into Egyptian slavery. (Ge 37:25-28; 39:1) In the days of Gideon the hordes that invaded Israel were described as both Midianites and Ishmaelites, one of the identifying marks of the latter being their gold nose rings.—Jg 8:24; compare Jg 7:25 and 8:22, 26.

The animosity Ishmael had toward Isaac seems to have been handed down to his descendants, even to the extent of hating the God of Isaac, for the psalmist, in enumerating those that are “the very ones intensely hating” Jehovah, includes the Ishmaelites. (Ps 83:1, 2, 5, 6) There were, however, evidently exceptions. Under the organizational arrangement instituted by David, Obil, who is referred to as an Ishmaelite, had supervision over the camels of the king.—1Ch 27:30, 31.

Muhammad (c. 570-632 C.E.), the founder of Islam, claimed to be an Ishmaelite descendant of Abraham.

The lineage of Ishmael shows a line of violence all through this narrative. What keeps my firm belief in the God of the Bible is usually a confirmation of what was written as spoken by God concerning Isaac and Ishmael.
That Ishmael will be a wild ass, and he shall be against everyone and everyone shall be against him. That statement could have lost over the years after several generations.
But to confirm the immutable word of God, generations after, a man woke up from nowhere and claimed that he's from the lineage of Ishmael and the curse and blessings of Ishmael came upon him.
Of course, the troubles in the world today is as designed by God. Sometimes I worry less when ISIS, Boko Haram and the many terrorists groups live up to God's pronouncements as concerned Ishmael which the Islamic faith traces her lineage.
Good or bad, it's the will of God.