Surih 37
99. He said: "I will go to my Lord! He will surely guide me
100. "O my Lord! Grant me a righteous (son)!"
101. So We gave him the good news of a forbearing son.
102. Then, when (the son) reached (the age of) (serious) work with him, he said: "O my son! I have seen in a vision that I offer thee in sacrifice: now see what is thy view!" (The son) said: "O my father! Do as thou art commanded: thou will find me, if Allah so wills, one of the steadfast!"
103. So when they had both submitted (to Allah), and he had laid him prostrate on his forehead (for sacrifice),
104. We called out to him "O Abraham! ...
105. "Thou hast already fulfilled the vision!" - thus indeed do We reward those who do right.
Isaac is mentioned further on in the same surih:
112. And We gave him the good news of Isaac - a prophet,- one of the Righteous.
113. We blessed him and Isaac: but of their progeny are (some) that do right, and (some) that obviously do wrong, to themselves.
Let me help you using verses in the Qur'an
The following Surah speaks of Abraham's wife Sarah and the
good news that she would have a son and call him
Isaac.
And his wife was standing by, wondering. Then We announced to her
the good news of Isaac, and from the progeny of Isaac, Jacob. Surah 11:71
Next Surah speaking of the sacrifice:
"O my Lord, grant me a righteous (son)!" So We gave him the
good news of a boy ready to suffer and forbear. Then when (the son) reached (the age of) (serious) work with him, he said, "O my son, I see in a vision that I offer thee in sacrifice. Now see what is thy view!" (The son) said, "O my father, do as thou art commanded. Thou will find me if Allah so wills one practicing patience and constancy!" So when they had both submitted their wills (to Allah) and he had laid him prostrate on his forehead (for sacrifice), We called out to him, "O Abraham, thou hast already fulfilled the vision!" Thus indeed do we reward those who do right. For this was obviously a trial -- and We ransomed him with a momentous sacrifice. -- Surat-us Saffat (37):99-107
Notice in this Surah that the name of the son is not given but it does say that the birth of this son was "good news."
There is no account of Ishmael's birth in the Qur'an that I could find.
Next Surah:
Has the story reached thee of the honored guests of Abraham? Behold, they entered his presence and said 'Peace!" He said "Peace". ... They said, "Fear not," and they gave him
glad tidings of a son endowed with knowledge.
But his wife came forward (laughing) aloud! She smote her forehead and said, "A barren old woman! " They said, "Even so has thy Lord spoken: and He is full of wisdom and knowledge." -- Surat-uz Zariyat (51):24-25, 28-30
This Surah is also talking about Sarah and Isaac. Notice we have the "good news/glad tidings" expression.
Next Surah:
Peace and salutation to Abraham! Thus indeed do we reward those who do right. For he was one of Our believing Servants. And We gave him
the good news of Isaac - a prophet -
one of the righteous. We blessed him and Isaac. -- Surat-us Saffat (37):109-113
Notice the phrases "and they gave him glad tidings of a son and "We gave him the good news of Isaac.
To my knowledge there is no Surah that refers to Ishmael as glad tidings or good news.
Notice what the commentary in my Qur'an says about this:
"The boy thus born was according to Muslim tradition (which however is not unanimous on this point) the first-born of Abraham viz. Ismail."
Why would this matter be "according to Muslim tradition" if the Qur'an was clear about who the son was? Why is the Qur'an so ambiguous?
I think the Qur'an confirms that it was Isaac and not Ishmael who God asked Abraham to sacrifice. The Qur'an is correct and the tradition is wrong.
The New Testament confirms it was Isaac.
"By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises was ready to offer up his only son ..." (Hebrews 11:17, R.S.V.).
"Was not Abraham our father justified by works, when he offered up his son Isaac upon the altar?" (James 2:21, R.S.V.)
