Make up a story: to create a story that is not true.

embellishment

I did not find داستان پردازی in these verses but here I write one of the best translations of these verses done by Pickhtall.
90 Pickthal: And they say: We will not put faith in thee till thou cause a spring to gush forth from the
91 Pickthal:Or thou have a garden of date-palms and grapes, and cause rivers to gush forth therein abundantly;
92 Pickthal:Or thou cause the heaven to fall upon us piecemeal, as thou hast pretended, or bring Allah and the angels as a warrant;
93 Pickthal:Or thou have a house of gold; or thou ascend up into heaven, and even then we will put no faith in thine ascension till thou bring down for us a book that we can read. Say (O Muhammad): My Lord be Glorified! Am I aught save a mortal messenger?