Pahaṃsati¹

to strike, beat (a metal), rub, sharpen (a cutting instrument, as knife, hatchet, razor etc.) Ja.i.278 Ja.ii.102 (pharasuṃ); Dhp-a.i.253 (khuraṃ pahaṃsi sharpened the razor; corresponds to ghaṭṭeti in preceding context)
pp pahaṭṭha¹ & pahaṃsita¹ (q.v.).

pa + haṃsati¹ = ghaṃsati¹, of ghṛṣ to rub, grind

Pahaṃsati²

to be pleased, to rejoice; only in pp. pahaṭṭha² & pahaṃsita² (q.v.), and in Pass. pahaṃsīyati to be gladdened, to exult Mil.326 (+ kuhīyati). See also sam˚.

pa + haṃsati² = hassati, of hṛṣ to be glad, cp. ghaṃsati²