Akkadian

pašāḫu - to rest, to calm down (CAD P 227, AHw. 840, EDA I 422)

Derived words: mušapšiḫu (a part of a door) (CAD M₂ 259, AHw. 681); pašāḫiš ‘in peace’ (AHw. 840); pašāḫu ‘tranquility’ (CAD P 227); pašḫu ‘resting’ (CAD P 251, AHw. 844); pušḫu ‘soothing’ (SAD I); šupšuḫu ‘calm’ (AHw. 1280); tapšaḫu ‘resting place’ (CAD T 194, AHw. 1322); tapšīḫu ‘relief’ (CAD T 194, AHw. 1323); tapšuḫtu ‘rest, relief’ (CAD T 195, AHw. 1323).
The etymology of the Akkadian verb is not yet fully clarified (Huehnergard 1991a:694). It may be related either to PWS *pŝḥ ‘to rejoice’ or to PCS *pšḥ ‘to be spacious’.