All Mankind are the Offspring of Adam
Allah states;
هُوَ الَّذِي خَلَقَكُم مِّن نَّفْسٍ وَاحِدَةٍ
It is He Who has created you from a single person,
Allah states that He has created all mankind from Adam, peace be upon him, and from Adam, He created his wife, Hawwa and from them, people started to spread.
Allah said in other Ayat,
يأَيُّهَا النَّاسُ إِنَّا خَلَقْنَـكُم مِّن ذَكَرٍ وَأُنْثَى وَجَعَلْنَـكُمْ شُعُوباً وَقَبَأيِلَ لِتَعَـرَفُواْ إِنَّ أَكْرَمَكُمْ عَندَ اللَّهِ أَتْقَـكُمْ
O mankind! We have created you from a male and a female, and made you into nations and tribes, that you may know one another. Verily, the most honorable of you with Allah is that (believer) who has Taqwa. (49;13)
and,
يَـأَيُّهَا النَّاسُ اتَّقُواْ رَبَّكُمُ الَّذِى خَلَقَكُمْ مِّن نَّفْسٍ وَحِدَةٍ وَخَلَقَ مِنْهَا زَوْجَهَا
O mankind! Have Taqwa of your Lord, Who created you from a single person, and from him He created his wife. (4;1)
In this honorable Ayah, Allah said;
وَجَعَلَ مِنْهَا زَوْجَهَا لِيَسْكُنَ إِلَيْهَا
And (then) He has created from him his wife, in order that he might enjoy the pleasure of living with her.
so that he is intimate and compassionate with her. Allah said in another Ayah,
وَمِنْ ءايَـتِهِ أَنْ خَلَقَ لَكُم مِّنْ أَنفُسِكُمْ أَزْوَجاً لِّتَسْكُنُواْ إِلَيْهَا وَجَعَلَ بَيْنَكُم مَّوَدَّةً وَرَحْمَةً
And among His Signs is this, that He created for you wives (spouses) from among yourselves, that you may find repose in them, and He has put between you affection and mercy. (30;21)
Indeed, there is no intimacy between two souls like that between the spouses. This is why Allah mentioned that the sorcerer might be able with his trick to separate between a man and his wife (thus indicating the difficulty of separating them in normal circumstances).
Allah said next,
فَلَمَّا تَغَشَّاهَا
When he covered her,
meaning had sexual intercourses with her.
حَمَلَتْ حَمْلً خَفِيفًا
she became pregnant and she carried it about lightly,
in reference to the first stage of pregnancy when the woman does not feel pain, for at that time, the fetus will be just a Nutfah (the mixture of the male and female discharge), then becomes an Alaqah (a piece of thick coagulated blood) and then a Mudghah (a small lump of flesh).
Allah said next,
فَمَرَّتْ بِهِ
and she carried it about,
According to Mujahid,
she continued the pregnancy,
Al-Hasan, Ibrahim An-Nakha`i and As-Suddi said similarly.
Maymun bin Mahran reported that his father said,
"She found the pregnancy unnoticeable."
Ayub said,
"I asked Al-Hasan about the Ayah,
فَمَرَّتْ بِهِ
(and she carried it about) and he said,
`Had you been an Arab, you would know what it means! It means that she continued the pregnancy (through its various stages)."'
Qatadah said,
فَمَرَّتْ بِهِ
(and she carried it about (lightly).), means, it became clear that she was pregnant.
Ibn Jarir commented, "This Ayah means that the liquid remained, whether she stood up or sat down."
Al-`Awfi recorded that Ibn Abbas said,
"The semen remained in, but she was unsure if she became pregnant or not,
فَلَمَّا أَثْقَلَت
Then when it became heavy,
she became heavier with the fetus",
As-Suddi said,
"The fetus grew in her womb."
دَّعَوَا اللّهَ رَبَّهُمَا لَيِنْ اتَيْتَنَا صَالِحاً
.
they both invoked Allah, their Lord (saying);"If You give us a Salih child,
if he is born human in every respect.
Ad-Dahhak said that Ibn Abbas commented,
"They feared that their child might be born in the shape of an animal!"
while Abu Al-Bakhtri and Abu Malik commented,
"They feared that their newborn might not be human."
Al-Hasan Al-Basri also commented,
"If You (Allah) give us a boy."
لَّنَكُونَنَّ مِنَ الشَّاكِرِينَ
فَلَمَّا اتَاهُمَا صَالِحاً جَعَلَ لَهُ شُرَكَاء فِيمَا اتَاهُمَا
فَتَعَالَى اللّهُ عَمَّا يُشْرِكُونَ