One whose evil deed done is covered by good illumines this world like the moon freed from clouds.

Yassa pāpaṃ kataṃ kammaṃ kusalena pidhīyati — whose evil deed is covered by good: pidhīyati is to cover, overcome. It is not about erasing past actions but overcoming them with positive actions that counteract their effect. Karma is not magically annulled but can be transformed by practice.

The same image of the moon behind clouds reinforces the teaching: evil actions are clouds that obscure natural luminosity. Good actions do not create that luminosity — they reveal it by dispersing clouds.

Somaṃ lokaṃ pabhāseti — illumines this world: the repetition of the second half of verse 172 with new first cause creates a double path of illumination: leaving negligence (172) and covering evil with good (173).

This verse is especially relevant for those burdened with guilt or remorse over past actions. One is not asked to deny the past but to actively overcome it. The past cannot be changed but its influence can be counteracted by present actions.