Retirement tax questions

I don't see anything in the IRS tax code that says pre-tax or post-tax (Roth) payroll deferral contributions to my 401K cannot count as repayment of a CARES withdrawal.  If I've missed something, can someone please point me to it?  Any money I put into the 401k account after the date of my CARES withdrawal is essentially me putting the money back in and should count towards repayment.  I realize there is an argument against doing this with pre-tax dollars because then you're reducing your taxable income twice, but I don't see anything in the tax code disallowing that.  

 

Thanks for any help/insights.  Just trying to navigate this thing...