64 Pa. Stat. § 132
Whenever it shall, by the original receipts, or other legal voucher, or by the entries made in his books, appear to the receiver general, that any person or persons have paid into the land office any moneys or certificate, for lands granted to them by virtue of warrants issued after the first day of April, 1784, and which they have not obtained, or that they have paid any moneys or certificates over and above what was due to the commonwealth for the lands obtained by virtue of such warrants, he shall carry the said money or balance to the credit of such person or persons, his, her, or their heirs, executors, administrators, or assigns, in payments already due, or hereafter to become due to the commonwealth, for the purchase of any lands within the same, together with lawful interest for the same, from the time of the original payment to the time of such credit being applied for and made.
64 P.S. § 132