A Dangerous Declaration By Stokes?

First Test, Rawalpindi (day four of five)
England 657 (Brook 153, Crawley 122, Pope 108, Duckett 107) & 264-7 dec.
Pakistan 579 (Babar 136, Imam 121, Shafique 114, Jacks 6-161) & 80-2 (Imam 43*)
Pakistan need further 263 to win