Walaqad AAahidna ila adama min qablu fanasiya walam najid lahu AAazma (surah TaHa: 115)

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

(20:115) We *92 gave a command to Adam before this *93 , but he forgot it, and We did not find firmness of purpose in him: *94

Wa laqad `ahidnaaa ilaaa Aadama min qablu fanasiya wa lam najid lahoo `azmaa

*92) From here begins a new discourse, which probably was sent down some time after the preceding discourse (see E.N. 90), and it was incorporated in this Surah by the command of Allah because both deal with the same theme. The following are the similarities between the two: (1) Both the discourses remind mankind of the "forgotten lesson", the Admonition, which Allah had taught man on the occasion of his creation.
(2) Both teach that it is Satan who seduces man to forget that lesson. He succeeded in this by causing his first parents to forget it; since then he has been forgetting it over and over again and, therefore, has been cautioned against this.
(3) Both warn man that his ultimate success or failure depends upon his attitude towards this "Admonition."
(4) Both warn mankind to discriminate between an inadvertent error and an intentional rebellion and their consequences. If man (like Prophet Adam and his offspring and the magicians of Pharaoh) realizes that he has been seduced by Satan, his eternal enemy, and then repents of his error, he is forgiven. But there is no forgiveness for intentional rebellion as was the case with Satan, Pharaoh and the Samiri.
*93) The story of Prophet Adam has already been stated in 11: 30-39, VII: 11-27, 189, XV: 28-42, XVII: 61-65 and XVIII: 51-52. But at every place only that part of the story which was relevant to the context has been cited. Therefore, in order to understand the whole story well, one should read it in all the Surahs along with the relevant E.N's.
*94) This means that he disobeyed the Command because he lacked the firmness of purpose and not because of intentional rebellion. He did not say, "I don't care a fig for Allah. If it is His Command, let it be. I will do whatever I like. Who is Allah to intervene in my private affairs?"
On the contrary, he disobeyed because he forgot Allah's Command, and did not show firmness of purpose and determination against the temptations presented by Satan. This is shown by his subsequent repentance.