Assuredly We had made a covenant with Adam (and forbidden him to approach a tree in the Garden), but he acted forgetfully. We did not find resolve in him (at that moment)
(Without Divine guidance of Revelation man is easily fallible.) And indeed, long ago We made a covenant with Adam (the mankind) that he would hold fast to Our Commands, but he forgot, and We found no constancy in him. (Adam = Mankind (2:30-38), (7:11-25))
And truly, (far) earlier than this, We had given a strict command to Adam but he forgot. And We did not observe in him any intention (to disobey) at all (it was just an omission)