The Prophets - 21:26
"They said: "The Most Merciful has taken a child". He is exalted. But they are honorable servants."
The gravity of ascribing children to Allah:
Mary/19:88
"They even said: "The Most Merciful has taken a child"
وَقَالُوا اتَّخَذَ الرَّحْمٰنُ وَلَداًۜ
Mary/19:90
Because of this arrogance, almost the heavens will be torn asunder, the earth will split and the mountains will collapse.
تَكَادُ السَّمٰوَاتُ يَتَفَطَّرْنَ مِنْهُ وَتَنْشَقُّ الْاَرْضُ وَتَخِرُّ الْجِبَالُ هَداًّۙ
Mary/19:92
It does not befit the Most Merciful to have children.
وَمَا يَنْبَغ۪ي لِلرَّحْمٰنِ اَنْ يَتَّخِذَ وَلَداًۜ
Mary/19:93
Whoever is in the heavens and the earth will come to the Most Merciful as a servant.
اِنْ كُلُّ مَنْ فِي السَّمٰوَاتِ وَالْاَرْضِ اِلَّٓا اٰتِي الرَّحْمٰنِ عَبْداًۜ
The Cattle/6:101
He it is Who created the heavens and the earth out of nothing. How can He have a child when He has no partner? He is the Creator of all things and He is All-Knowing.
بَد۪يعُ السَّمٰوَاتِ وَالْاَرْضِۜ اَنّٰى يَكُونُ لَهُ وَلَدٌ وَلَمْ تَكُنْ لَهُ صَاحِبَةٌۜ وَخَلَقَ كُلَّ شَيْءٍۚ وَهُوَ بِكُلِّ شَيْءٍ عَل۪يمٌ
The Night Journey/17:40
Has your Lord chosen sons for you and has He taken for Himself daughters from the angels? You are making a very great claim.
اَفَاَصْفٰيكُمْ رَبُّكُمْ بِالْبَن۪ينَ وَاتَّخَذَ مِنَ الْمَلٰٓئِكَةِ اِنَاثاًۜ اِنَّكُمْ لَتَقُولُونَ قَوْلاً عَظ۪يماً۟