30. In order to understand the significance of this argument the reader should keep in view (Ayats 148-150 and E.N.s 124-126 of Surah Al-Anaam), for this has been cited and answered there.
31. That is, your argument is not a new one but the same old one which had always been offered by erroneous people who went before you. Today you are, like them, excusing yourselves for your deviation and evil conduct, saying that it is the will of God. You know that this is a lame excuse that has been invented to delude yourselves, and to escape from admonition.
This answer also contains a subtle retort to the objection of the disbelievers that the Quran consisted merely of old stories of the ancients (Ayat 24). They meant to imply that the Prophet (peace be upon him) had nothing new to offer. So he was repeating the same old stories that had been repeated over and over again since the time of Prophet Noah (peace be upon him). The retort is this: If the Prophet (peace be upon him) was not presenting anything new but was reciting the old stories of the ancients, you yourselves are not putting forward any new excuse in defense of your evil deeds, but the same old excuse that was put forward by the people who went before you.