11 U.S. Code § 928 - Post petition effect of security interest
(a) Notwithstanding section 552 (a) of this title and subject to subsection (b) of this section, special revenues acquired by the debtor after the commencement of the case shall remain subject to any lien resulting from any security agreement entered into by the debtor before the commencement of the case.
Source(Added Pub. L. 100–597, § 8,Nov. 3, 1988, 102 Stat. 3029.)