In the Holy Koran there are the verses in which existence of the Purgatory is proved:
1) Since whenever death comes to day one of them, he says, “My Lord, send me back, so I may act honorably I may have left behind.” Indeed not!
It is merely a remark he s making. Beyond them there lies a barrier till the day when they will be raised up again (23:99-100)
The term “barrier” in the verse refers to the Purgatory where the dead will stay in till the Resurrection.
2) why no –when [your soul] leaps to your throat [at death] and you are then observing , we are even Nearer to it then you are , even though you do not notice it, provided you are not under any obligation , answer back if you are so truthful….! Thus if he is one of those who are drawn close, [the will have] contentment, fragrance, and a garden of bliss, while if he is one of the companions on the Right: “peace be upon you” [will be the greeting] from the companions on the Right. However if he is one the mistaken rejectors a welcome of scolding water plus a roasting in Heads [will await him] (56:83-94)