The Quran says that when the night and the day overlap, they make a ball (sphere):
٥ خَلَقَ السَّمَاوَاتِ وَالْأَرْضَ بِالْحَقِّ ۖ يُكَوِّرُ اللَّيْلَ عَلَى النَّهَارِ وَيُكَوِّرُ النَّهَارَ عَلَى اللَّيْلِ ۖ وَسَخَّرَ الشَّمْسَ وَالْقَمَرَ ۖ كُلٌّ يَجْرِي لِأَجَلٍ مُسَمًّى ۗ أَلَا هُوَ الْعَزِيزُ الْغَفَّارُ
The Arabic word "Kura كرة" means ball; the Quran used its verb "Yukawer يُكَوِّرُ" meaning to make into a ball. The Quran says that the overlapping of the night and the day makes a ball (sphere).
"ALL MOVE (Kullon Yajree كُلٌّ يَجْرِي)" here the Quran is referring to ALL MOVING, not only the sun and moon but also Earth. In Arabic grammar there is difference between the singular (one), binary (two) and plural (three or more). The reference to binary is "Kulahuma Yajreean كلاهما يجريان" however the Quran said "Kullon yajree كُلٌّ يَجْرِي" referring to the plural (three or more). Since the sun and moon are just two but the Quran refers to three or more then according to the Quran all the three move: sun, moon and Earth.
How could an illiterate man who lived 1400 years ago have known that all move sun moon and Earth?
The Quran says that Earth has a diameter (diameter is twice the radius).
٣٣ يَا مَعْشَرَ الْجِنِّ وَالْإِنْسِ إِنِ اسْتَطَعْتُمْ أَنْ تَنْفُذُوا مِنْ أَقْطَارِ السَّمَاوَاتِ وَالْأَرْضِ فَانْفُذُوا ۚ لَا تَنْفُذُونَ إِلَّا بِسُلْطَانٍ
Diameter in Arabic is Kutr قطر. Its plural is Aktar اقطار. Radii and diameters are properties of circles or spheres only. This conforms with the previous verse, to make into a ball [Yukawer يُكَوِّرُ].
How could an illiterate man who lived 1400 years ago have known that Earth has a diameter?
"Sateh سطح" in Arabic means surface however this surface can have any shape. Surface of the moon means " Sateh Al-Kamar سطح القمر " and has the shape of a sphere. It could have the shape of a saddle.
This saddle shape is one type of "sateh سطح". It could have any shape but unfortunately "sateh سطح" was mistranslated to flat.
"Sateh سطح" in Arabic means any surface however it was mistranslated to flat. Flat in Arabic is "musattah مسطح" however it was not used in the entire Quran.
٧ وَالْأَرْضَ مَدَدْنَاهَا وَأَلْقَيْنَا فِيهَا رَوَاسِيَ وَأَنْبَتْنَا فِيهَا مِنْ كُلِّ زَوْجٍ بَهِيجٍ
The Quran says that God spread out the Earth 'والارض مددناها' meaning increase in surface area during formation. 'Madda' in Arabic means 'spread out', however it was also mistranslated to 'flat'.
The Quran says that God spread out Earth, that is, increased the surface area. Our solar system is 4.57 billion years old. Earth started accreting concurrently with the sun and our neighbouring planets 4.57 bln years ago. However during the accretion process the radius of Earth was not spontaneously 6400 km but rather started a few kilometers long and progressively increased. The surface area is a function of the radius (surface area = 4πR^2), that is, as the radius increases the surface area increases. So the Quran correctly described the surface area as increasing. (This is contrary to the Bible where the creation of Earth was spontaneous.)
How could an illiterate man who lived 1400 years ago have known that Earth is a sphere?
The Quran (Koran, the book of Islam) contains scientific knowledge that could not have been known 1400 years ago. It ranges from basic arithmetics to the most advanced topics in astrophysics. You are invited to go through those miracles and judge for yourself.