What does « Leaf / Silver » mean in the Quran?

And with Him are the keys of the unseen; none knows them except Him. And He knows what is on the land and in the sea. Not a leaf falls but that He knows it. And no grain is there within the darknesses of the earth and no moist or dry [thing] but that it is [written] in a clear record.

So he made them fall, through deception. And when they tasted of the tree, their private parts became apparent to them, and they began to fasten together over themselves from the leaves of Paradise. And their Lord called to them, "Did I not forbid you from that tree and tell you that Satan is to you a clear enemy?"

And similarly, We awakened them that they might question one another. Said a speaker from among them, "How long have you remained [here]?" They said, "We have remained a day or part of a day." They said, "Your Lord is most knowing of how long you remained. So send one of you with this silver coin of yours to the city and let him look to which is the best of food and bring you provision from it and let him be cautious. And let no one be aware of you.

And Adam and his wife ate of it, and their private parts became apparent to them, and they began to fasten over themselves from the leaves of Paradise. And Adam disobeyed his Lord and erred.