True you can purchase immediately after you close, however, there is a clause in the short sale approval letter that clearly states that if the bank discovers there was "fraud" committed they can sue you for the forgiven amount (balance minus the proceeds they received).
Hope this helps and good luck!
However, as suggested already, if you have (are hiding) that much cash, you're likely (I'm not a lawyer, so this isn't legal advice) committing fraud by telling your lender that you have a financial hardship.
Don't do it.
I have that situation with a customer and the Bank find out a year later and now they charging her the full amount that she originally owed.
Best of Luck,
Century 21 Tenace
Let's look at a general picture. I am not giving you any legal or tax advice and recommend you consult with those trusted resources.
In a short sale the lender wants to see your bank accounts and see that you have a hard ship. If you have money you probably don't have a hard ship.
The laws of state vary so you will want to check on consequences of the lender coming after you after a short sale and any tax you may have to pay due to the release of the financial burden.
If you were to purchase first before or after short selling, there will be no credit check on the purchase so that is removed.
If you purchase before short selling the funds are no longer available as assets. Your current lender may look for homes you own.
Have you already closed on your short sale? If not, there are so many variables that can affect the outcome, I encourage you to talk with the trusted professionals so that you take the best course of action for your goal.
Have an amazing day!