1400 years ago people knew that honey was very viscous. However it was impossible for them to tell which is more viscous water, wine or milk.
List of viscositiesViscosity is a material property which describes the resistance of a fluid to shearing flows. It corresponds roughly to the intuitive notion of a fluid's 'thickness'. For instance, honey has a much higher viscosity than water.
The least viscous is water, milk, wine then honey. This was known recently however this was portrayed in the Quran 1400 years before it was discovered. Paradise has rivers of water, milk, wine and honey:
١٥ مَثَلُ الْجَنَّةِ الَّتِي وُعِدَ الْمُتَّقُونَ ۖ فِيهَا أَنْهَارٌ مِنْ مَاءٍ غَيْرِ آسِنٍ وَأَنْهَارٌ مِنْ لَبَنٍ لَمْ يَتَغَيَّرْ طَعْمُهُ وَأَنْهَارٌ مِنْ خَمْرٍ لَذَّةٍ لِلشَّارِبِينَ وَأَنْهَارٌ مِنْ عَسَلٍ مُصَفًّى ۖ وَلَهُمْ فِيهَا مِنْ كُلِّ الثَّمَرَاتِ وَمَغْفِرَةٌ مِنْ رَبِّهِمْ ۖ كَمَنْ هُوَ خَالِدٌ فِي النَّارِ وَسُقُوا مَاءً حَمِيمًا فَقَطَّعَ أَمْعَاءَهُمْ
Rivers are flowing liquids. Those liquids are arranged by the correct viscosity order: water, milk, wine then honey.
How could an illiterate man who lived 1400 years ago have known about viscosity?
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.