( وَإِذَا تُتْلَىٰ ) (And when Our verses are recited): When the verses are recited in sequence and with contemplation,  in accordance to the their original revelation.

( وَإِذَا تُتْلَىٰ عَلَيْهِمْ آيَاتُنَا) (And when Our verses are recited to them): The Arabic word of (Verses) means miracles, so that, the verses of the Holy Quran are miracles.

( قَالُوا قَدْ سَمِعْنَا ) (they say, “We have heard): Referring to the Holy Quran.

( لَوْ نَشَاءُ لَقُلْنَا مِثْلَ هَٰذَا ) (If we willed, we could say [something] like this): They challenged the Prophet (saws) claiming that they could bring forth a book similar to the Holy Quran.

( إِنْ هَٰذَا إِلَّا أَسَاطِيرُ الْأَوَّلِينَ) (This is not but legends of the former peoples): Their claim against the Holy Quran is that it is mere legends and myths of the old times. After which Allah (swt) challenged them by saying:

 وَإِن كُنتُمْ فِي رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا بِسُورَةٍ مِّن مِّثْلِهِ وَادْعُوا شُهَدَاءَكُم مِّن دُونِ اللَّهِ إِن كُنتُمْ صَادِقِينَ

(And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful.) (Al-Baqara: 23)

 أَمْ يَقُولُونَ افْتَرَاهُ ۖ قُلْ فَأْتُوا بِعَشْرِ سُوَرٍ مِّثْلِهِ مُفْتَرَيَاتٍ وَادْعُوا مَنِ اسْتَطَعْتُم مِّن دُونِ اللَّهِ إِن كُنتُمْ صَادِقِينَ

(Or do they say, “He invented it”? Say, “Then bring ten surahs like it that have been invented and call upon [for assistance] whomever you can besides Allah, if you should be truthful.”) (Hud: 13)