Wa-itha qeela lahum matha anzala rabbukum qaloo asateeru al-awwaleen (surah Nahl: 24)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(16:24) And *21 when they are asked, "What is it that your Lord has sent down"?, they say these are mere fairy tales of the ancients. *22

Wa izaa qeela lahum maazaaa anzala Rabbukum qaaloo asaateerul awwaleen

*21) In the preceding verse (23) those puffed up people, who were rejecting the Message were warned that Allah had full knowledge of all their "deeds." Now from v. 24 the Qur'an takes up those "deeds" one by one and deals with the arguments they presented against the Messenger, the objections they raised and the lame excuses they invented for their rejection, and reproaches and admonishes them.
*22) One of their cunning devices was to create doubts about the Qur'an. Whenever outsiders came tc visit Makkah, they would naturally make enquiries about the Qur'an, which the Holy Prophet declared, was being sent down to him by Allah. The disbelievers would answer that it contained merely fairy-tales of the ancients. They would say such things in order to create doubts in the minds of the inquirers so that they should not take any interest in the Message of the Holy Prophet.