Comparative evidence

leh₁

• Hitt. la-, lai- 'untie', 'unbind', 'detach', 'release', 'relieve', 'dispel', 'remove', 'loosen' (CHD L-N: 1ff., EDHIL: 509)

• Hitt. le 'not' (prohibitive particle) (EDHIL: 523)

References

CHD = Guterbock H.G., H.A. Hoffner, Th.P.J. van den Hout (eds.), 1980 - . The Hittite Dictionary of the Oriental Institute of the University of Chicago. Chicago.
EDHIL = Kloekhorst, A. 2008. Etymological Dictionary of the Hittite Inherited Lexicon. Brill.