Abraham’s son Ishmael.
Those sentences which are colored in orange are from Maharishi Dayananda Saraswati book Satyarth Prakash (The Light of Truth) and those which are colored in black are Jerry Thomas’s response.
"And these are the names of the sons of Ishmael, by their names, according to their generations: the first-born of Ishmael, Nebajoth: and Kedar, and Adbeel, and Mibsam. And Mishma, and Dumah,a nd Massa, Hadar, and Tema, Jetur, Naphish, and Kedemah." (25: 13, 15.)C. This Ishmael was Abraham's son born of Haggar, his handmaid.
Answer: So far in this series of observations by Maharishi, this is the first correct observation. I give full marks for this observation. This Ishmael is indeed the son of Abraham.
Now, I am sure that Maharishi might not have understood the relevance of this passage.
In Genesis 17, when Abraham prayed for Ishmael, God told Abraham clearly that covenant will be established through Isaac but He will bless Ishmael by giving him twelve princes.
Genesis 17:20 And as for Ishmael, I have heard you. Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly. He shall beget twelve princes, and I will make him a great nation.
If you read the verse cited by Maharishi, you will know that God fulfilled His promise to Abraham and Ishmael had twelve sons who were princes.
The lesson that we learn is when the Holy God of the Bible gives a promise, He faithfully fulfills it. Amen.