﴿ كَلَّآ ۖ إِنَّا خَلَقْنَٰهُم مِّمَّا يَعْلَمُونَ ﴾

“Never! For, behold, We have created them out of something that they know [only too well]!”

(Nay, verily. Lo! We created them) i.e. the disbelievers of Mecca (from what they know) i.e. a sperm drop.