Genesis Chapter 21 Records Isaac’s Birth and Circumcision

Are birthdays celebrated by G-d’s chosen people, the Jews?

No record from Genesis to II Chronicles is found about birthday celebrations of godly people.

Ungodly, yes. I.e. Pharaoh of Egypt.

“The Birth of Isaac”
“Hagar and Ishmael Sent Away”
“Ishmael is Saved”

Hashem had remembered Sarah as He had said; and Hashem did for Sarah as He had spoken.
21:1
Abraham called the name of his son who was born to him – whom Sarah had borne him – Isaac.
21:3
Abraham circumcised his son Isaac at the age of eight days as God had commanded him.
:4
The child grew and was weaned. Abraham made a great feast on the day Isaac was weaned.
:8
So God said to Abraham, “Be not distressed over the youth or your slavewoman: Whatever Sarah tells you, heed her voice, since through Isaac will offspring be considered yours.
:12
He planted an “eshel” in Beer-sheba, and there he proclaimed the Name of Hashem, God of the Universe.
:33

1 And the Lord remembered Sarah as He had said, and the Lord did to Sarah as He had spoken.
2 And Sarah conceived and bore a son to Abraham in his old age, at the time of which God had spoken to him.
3 And Abraham named his son who had been born to him, whom Sarah had borne to him, Isaac.
4 And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him.
5 And Abraham was a hundred years old, when his son Isaac was born to him.
6 And Sarah said, “God has made joy for me; whoever hears will rejoice over me.”
7 And she said, “Who would have said to Abraham that Sarah would nurse children, for I have borne a son to his old age!”
8 And the child grew and was weaned, and Abraham made a great feast on the day that Isaac was weaned.
9 And Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, making merry.
10 And Sarah said to Abraham, “Drive out this handmaid and her son, for the son of this handmaid shall not inherit with my son, with Isaac.”
11 But the matter greatly displeased Abraham, concerning his son.
12 And God said to Abraham, “Be not displeased concerning the lad and concerning your handmaid; whatever Sarah tells you, hearken to her voice, for in Isaac will be called your seed.
13 But also the son of the handmaid I will make into a nation, because he is your seed.”
14 And Abraham arose early in the morning, and he took bread and a leather pouch of water, and he gave [them] to Hagar, he placed [them] on her shoulder, and the child, and he sent her away; and she went and wandered in the desert of Beer sheba.
15 And the water was depleted from the leather pouch, and she cast the child under one of the bushes.
16 And she went and sat down from afar, at about the distance of two bowshots, for she said, “Let me not see the child’s death.” And she sat from afar, and she raised her voice and wept.
17 And God heard the lad’s voice, and an angel of God called to Hagar from heaven, and said to her, “What is troubling you, Hagar? Fear not, for God has heard the lad’s voice in the place where he is.
18 Rise, pick up the lad and grasp your hand upon him, for I shall make him into a great nation.”
19 And God opened her eyes, and she saw a well of water, and she went and filled the pouch with water and gave the lad to drink.
20 And God was with the lad, and he grew, and he dwelt in the desert, and he became an archer.
21 And he dwelt in the desert of Paran, and his mother took for him a wife from the land of Egypt.
22 Now it came to pass at that time, that Abimelech and Phicol his general said to Abraham, saying, “God is with you in all that you do.
23 And now, swear to me here by God, that you will not lie to me or to my son or to my grandson; according to the kindness that I have done with you, you shall do with me, and with the land wherein you have sojourned.”
24 And Abraham said, “I will swear.”
25 And Abraham contended with Abimelech about the well of water that the servants of Abimelech had forcibly seized.
26 And Abimelech said, “I do not know who did this thing, neither did you tell me, nor did I hear [of it] until today. “
27 And Abraham took flocks and cattle, and gave them to Abimelech, and they both formed a covenant.
28 And Abraham placed seven ewe lambs by themselves.
29 And Abimelech said to Abraham, “What are these seven ewe lambs, which you have placed by themselves?”
30 And he said, “For these seven ewe lambs you shall take from my hand, in order that it be to me for a witness that I dug this well.”
31 Therefore, he named that place Beer sheba, for there they both swore.
32 And they formed a covenant in Beer-sheba, and Abimelech and Phicol his general arose, and they returned to the land of the Philistines.
33 And he planted an eishel in Beer-Sheba, and he called there in the name of the Lord, the God of the world.
34 And Abraham dwelt in the land of the Philistines for many days.