N.H. Rev. Stat. Ann. § 464-A:33
III. Before making any purchase under such license, the guardian of the estate shall take the following oath and file a certificate thereof in the office of the clerk:
"I, .......... , guardian of the estate of .......... , swear that in purchasing a homestead for my ward, I am acting in the best interests and to the utmost advantage for my ward, without any self-interest whatever."
Source. 1979, 370:1. 2011, 88:20, eff. July 1, 2011.