Genesis 21 tells us that Sarah and Abraham were still dwelling in the Philistine city of Gerar when Isaac was born. Since Sarah was ninety years old when Isaac was born, Abraham would have been 100 years old at that time. Jasher 21:11 reveals Ishmael was 14 years old when Isaac was born.
Eight days after Isaac was born, he was circumcised according to God’s commandment. Isaac grew and the day Isaac was weaned, Abraham had a great feast for him. The book of Jasher tells us that many people came to celebrate this event including Shem, Eber, Abimelech, Terah, Nahor, and many others. According to Rashi, this took place when Isaac was 24 months old. 
Next, Genesis 21:9 says Sarah saw Ishmael mocking Isaac. I always assumed Ishmael mocked Isaac during the great feast for Isaac’s weaning but Jasher 21:13 indicates Isaac was 5 years old at the time this took place. We tend to think that Ishmael was laughing or making fun of something that Isaac did but this is not the case.
According to Strong’s concordance, “tsachaq” can mean to laugh, mock, play, or make sport. Rashi indicates this can be: an expression of idolatry, illicit sexual relations, or of murder. This may seem very odd to us but Jasher 21:13 confirms one of Rashi’s expressions by indicating that Ishmael sat across from Isaac, pointed his bow and arrow at him, and intended to kill him. Ishmael literall made sport of Isaac as if he were wild game! By this time, Ishmael would have been 19 years old and would have known exactly what he was doing. This was not foolish child’s play. It’s no wonder Sarah told Abraham to throw them out!
Genesis 21:14-18 tells us that Hagar and Ishmael wandered in the wilderness of Beersheba once they left Abraham’s dwelling. As the Bible describes Ishmael during this time, it uses the Hebrew word “yeled” which is translated as “boy” or “lad.” This word can also be translated as “young man;” therefore, the use of this word does not contradict the idea that Ishmael was 19 years old when they left Abraham’s home.
Some unknown time later, Ishmael and Hagar began to dwell in the wilderness of Paran. At that time Hagar took a wife for him from Egypt and eventually Ishmael fathered 12 nations as the Lord had promised.
It was a good thing that Ishmael did not kill Isaac with his bow and arrow many years ago. Because Isaac was spared, God was able to bring Jesus from his lineage. Even though Jesus died on a cross with nails in his hands and feet and a spear rammed through his side, He rose from the dead, is alive today in heaven, and is interceding on our behalf.
We, who are the Bride of Christ, currently find ourselves wandering in the wilderness of this world and fighting against principalities and unseen spiritual forces of darkness while trying to raise families that are devoted to the Lord.
Be assured, Jesus will eventually return to Jerusalem to defend His people from the Ishmaelites, Edomites, and Israel’s other enemies who already desire to kill them but they will be destroyed and cast out.
God’s people who wander and dwell throughout the earth will be brought together for an awesome wedding feast with prominent people like Adam, Noah, Shem, Abraham, Isaac, Jacob, all the prophets, apostles, and many others in attendance. What a day that will be!