ma.lach describes the heavens’ dissipation like smoke in contrast to what endures.

The attested use describes the heavens passing away or dissipating, in a verse that contrasts their transience with salvation and righteousness that endure.

1. Passing away like smoke · dominant

   In Isaiah 51:6, the Niphal perfect plural form occurs in the statement about the heavens; the APB renders the clause, “the heavens will dissipate like smoke,” before contrasting this with salvation that will be forever.

   Isaiah 51:6

In the Anselm Project Bible: In Isaiah 51:6 the APB presents the relevant clause as “the heavens will dissipate like smoke.” This rendering identifies the verse’s presentation rather than a precise English-token match.