HSAs are covered by section 223 of the US Code: <a rel="nofollow" target="_blank" href="
https://www.law.cornell.edu/uscode/text/26/223">https://www.law.cornell.edu/uscode/text/26/223</a>
There simply isn't anything the US code that treats interest earned within an HSA as a contribution to the HSA. Contributions are money that you deposit into the HSA. Section 223(d)(1)(A)(i) describes contributions as being *cash* that you add to the HSA.
