وَمَنْظَرُهُنَّ شَكْلٌ وَاحِدٌ لِلْأَرْبَعِ. كَأَنَّهُ كَانَ بَكْرَةٌ وَسْطِ بَكْرَةٍ.
And as for their appearances, they four had one likeness, as if a wheel had been in the midst of a wheel.