Genesis 21:9-13 meaning

Now that Sarah has a son, Isaac, she wants Ishmael, the son of Hagar the Egyptian, to leave their household, along with his mother. Ishmael is Abraham's son, borne to him by Hagar, and both are a painful presence to Sarah. Furthermore, Sarah wants to secure Isaac's inheritance when he grows up. Thus, Ishmael cannot stay, for he is Abraham's firstborn son and will have a better claim as the heir, unless he leaves.

Sarah observes Ishmael mocking Isaac. Perhaps Ishmael was ridiculing all the fuss being made over Isaac. The apostle Paul states that Ishmael "persecuted" Isaac (Galatians 4:29). Whatever he was doing in mockery, Sarah was enraged by Ishmael's actions. In anger, Sarah orders Abraham to banish Hagar and Ishmael, Drive out this maid and her son. We see the old rivalry between Sarah and Hagar reappearing. Earlier, Sarah expelled Hagar after Hagar began to despise Sarah once she became pregnant (Genesis 16:4-6). God met her and told her to return and submit to Sarah (Genesis 16:9)

Sarah states her concern: Ishmael shall not be an heir with my son Isaac. Her goal is to make sure her son receives his inheritance from Abraham, rather than Ishmael. Customarily, the older son of the household received the birthright inheritance, which gave them headship over the tribe. Sarah did not want them to share in the inheritance. Sarah reasoned that Isaac alone was the genuine heir and Ishmael should not share in Abraham's inheritance.

Abraham is caught in the middle of the matter and feels distressed. Ishmael is his son, born of his own body. Forcing Ishmael to leave grieved him. Abraham loved both Ishmael and Isaac and did not wish to send either of them away. The Mosaic law said (and the laws of this earlier time period might have reflected) that a first born son must have the birthright "double portion" inheritance right, even if the wife of the firstborn was not the favored wife (Deuteronomy 21:15-17). However, Hagar was not Abraham's wife, but rather Sarah's maid. Sarah's intent is to forfeit Ishmael's claim to the birthright inheritance as the firstborn by driving Hagar and Ishmael out of the household. Jephthah, one of Israel's judges, will later experience the same fate (Judges 11:1-3).

God reveals to Abraham what he is to do and confirms His plan for each child, Whatever Sarah tells you, listen to her. As the head of the household, Abraham must give the order of expulsion to Hagar.

God consoles Abraham by decreeing that through Isaac, and not through Ishmael, His purposes and promises to Abraham will be carried out, and his descendants shall be named (Romans 9:7; Hebrews 11:18). Isaac is the child of promise. Future generations will be blessed through this single child. So, we see a shift from Sarah's motivation to God's purposes. Two thousand years later the Apostle Paul will use this event to illustrate that reward of inheritance passes through promise rather than law. According to law and custom, Ishmael should gain the birthright inheritance to receive the reign. But God grants the inheritance to the child of promise, which are those who receive God's grace through faith (Galatians 4:21-31).

The Bible has a pattern of the second in line ascending over the first. Isaac ascended over Ishmael. Abel over Cain. Jacob over Esau. King David over King Saul. Jesus is the second Adam, the second Moses, the second Joshua (which was His Hebrew name), the second David, and the second Passover Lamb (1 Corinthians 15:45; Deuteronomy 18:15-19; Acts 2:29-36; Revelation 13:8). In each case He ascended over the first, who was a type of Him Who Was to Come. Humanity is apparently also the second race appointed to reign over the earth, and will ascend over the angels (Psalm 8; Hebrews 2:5-13). Those who overcome as Jesus overcame will reign with Jesus in the second (and greater) Jerusalem (Revelation 3:21; 21:10).

Hagar and Ishmael will not be left to an uncertain fate in the wilderness, a great future awaits Ishmael. God declares that He will make a nation also out of Ishmael, because he is also Abraham's descendant. Although God's covenant will not be kept through Ishmael, God will still bless him. Therefore, another promise that God gives Abraham is that He will make Ishmael's descendants a great nation. It should be noted that God also had promised that Abraham will father many offspring and peoples (Genesis 13:16, 15:5, 16:10, 17:5). By God's grace, Ishmael loses one reign but gains descendants. Unfortunately for Hagar, she did not know of God's promise until later (v. 18).