This was Gods promise to Abraham 'That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy'
this is the promise that God gave Hagar the Egyptian
'For God spoke unto Hagar and said, “And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.”
(Genesis 17:20)
There are 14 nations in the Middle east excluding Israel but there just so happens to be 12 nations that have the equivalent of a king (7 Sheikhs, 2 kings, 2 emirs, and 1 sultan.)
12
He will be a wild donkey of a man, and his hand will be against everyone, and everyone’s hand against him; he will live in hostility toward all his brothers.”
Ishmael only had one brother Isaac so the brothers God talks about here have to be the nations that comes from Ishmael. Then they will live in hostility of all his brothers means that they will stay close. But God says Ishmeal will beget twelve nations.
Another explaing of the prase. From christian source.
Genesis 16:10-12 meaning
The angel of the Lord promised Hagar she will have numerous descendants. He tells her to name the baby “Ishmael” and that he will, unlike Hagar, be a free and independent man who will bow to no one.
The divine command is followed by a divine promise. Encouraging Hagar, the angel promises she will have numerous descendants even while her first child is in her womb, saying,
I will greatly multiply your descendants so that they will be too many to count (v 10). This was similar to the promise given to Abram (Genesis 12:1-3, 15:1-6). God blessed Ishmael as Abram's descendant, but not as the line chosen to fulfill God's covenant with Abram. That blessing was reserved for Abram's chosen heir, who will be Isaac. This promise given to Hagar is fulfilled in a multitude of peoples (Genesis 25:13-16).
The angel told Hagar,
You will bear a son and you shall call his name Ishmael (v 11). Ishmael means "God hears." God had listened to her and acknowledged her complaint.
The Lord has given heed to your affliction (v 11), the angel tells Hagar. It is interesting here that Sarai had asked God to judge between her and Abram, with respect to Hagar's treatment of her (Genesis 16:5). Abram declined to mediate, yet God intercedes. He answers Sarai's request and His mediation restores the relationship. Sarai retains authority, but Hagar is promised her descendants will be liberated.
He will be a wild donkey of a man (v 12) indicates that like a wild donkey, Ishmael will have no masters. He will be independent, and hard to oppress (Job 24:5; Hosea 8:9).
His hand will be against everyone, And everyone's hand will be against him (v 12) indicates that Ishmael as well as his descendants will remain unconquered and independent (Genesis 25:18). After becoming Abram's wife, Hagar had been delivered back into Sarai's
power (Genesis 16:6). This is literally translated into Sarai's "hand." By saying
his hand will be against everyone the passage is saying he will have power to resist oppression from others. He will not be ruled.
While Hagar is asked to submit to Sarai, who has been a harsh master, she can do so with confidence in God's promise that her son will submit to no one. She may be oppressed, but through Ishmael her descendants will be free of oppression.
Ishmael would become the father of a great nation. Unlike his mother, he would not be a servant of others. Ishmael would have sufficient strength and resolve to resist capture and subjugation.
The phrase
he will live to the east (v 12) seems puzzling to fit into the context
. A literal rendering would be "before the face of his brethren." Some translations interpret "before the face" as "he will live in hostility toward his brethren." However, there is nothing in the text that indicates that "before the face" means hostility. In verse 6, Hagar fled "from the face" of Sarai, meaning from her presence. This phrase is better rendered "he will dwell in the presence of his brethren." The Bible records the sons of Ishmael joining with the sons of Isaac at the burial of Abraham (Genesis 25:9). No hostility between Israelites and Ishmaelites is noted in Genesis. Jacob's sons sell their brother Joseph to a caravan of Ishmaelites heading to Egypt (Genesis 37:25). But the episode appears simply as a commercial transaction. Also, Esau will take a wife from Ishmael's people (Genesis 28:9). Both instances support the idea that the Ishmaelites would be in the vicinity.
There are twelve sons of Ishmael (Genesis 25:16). Much later in the history of Israel, there are Ishmaelites who integrate into Israel (1 Chronicles 2:17; 27:30). Also much later, there are adversarial interactions. Gideon delivers Israel from oppressing Ishmaelites (Judges 8:24). And Psalm 83:6, written in the era of the kings of Judah, speaks of Ishmaelites who seek harm to Israel.