So I have to prepare another document and send to IRCC? Or I should wait till I am asked to provide the documentYou will have to explain the large sum if it happened in 6 months. You can’t use the previous explanation, because that was a different moment for a different sum of money. For example, if in your first POF you explained the sum with a gift deed, and after spending the money you receive another sum from your parents, you will need another deed explaining that one, because it’s not the same gift.