25 U.S. Code § 3306 - Limitations on use of funds
(a) Use for religious purposes
None of the funds made available under this subchapter may be used for study at any school or department of divinity or for any religious worship or sectarian activity.
(b) Interest on funds
No interest or other income on any funds made available under this subchapter shall be used for any purpose other than those for which such funds may be used.
(1) In general
Except as otherwise provided in this subsection, the Secretary shall make payments to grantees under this subchapter in two payments—
(A) one payment to be made no later than October 1 of each fiscal year in an amount equal to one-half the amount paid during the preceding fiscal year to the grantee or a contractor that has elected to have the provisions of this subchapter apply, and
(d) Investment of funds
(1) Treatment as tribal property
Notwithstanding any other provision of law, any interest or investment income that accrues on any funds provided under this subchapter after such funds are paid to the Indian tribe or tribal organization and before such funds are expended for the purpose for which such funds were provided under this subchapter shall be the property of the Indian tribe or tribal organization and shall not be taken into account by any officer or employee of the Federal Government in determining whether to provide assistance, or the amount of assistance, under any provision of Federal law.
(2) Investment requirements
Funds provided under this subchapter may be—
(A) invested by the Indian tribe or tribal organization only in obligations of the United States or in obligations or securities that are guaranteed or insured by the United States, or