﴿ فَٱسْتَفْتِهِمْ أَهُمْ أَشَدُّ خَلْقًا أَم مَّنْ خَلَقْنَآ ۚ إِنَّا خَلَقْنَٰهُم مِّن طِينٍۢ لَّازِبٍۭ ﴾

“AND NOW ask those [who deny the truth] to enlight­en thee: Were they more difficult to create than all those [untold marvels] that We have created? - for, behold, them have We created out of [mere] clay commingled with water!”

Please check ayah 37:19 for complete tafsir.