Learn French: Que le ciel bénisse notre gloire !

This is a classic third-person wish or command. In French, you can express a strong wish or indirect command by starting an independent clause with Que followed by the subjunctive mood. It translates to 'Let...' or 'May...' in English. Here, it expresses a heartfelt wish: 'May heaven bless...'.

Is bénisse in the subjunctive here? How is it formed?

Yes, bénisse is the present subjunctive of the regular -ir verb bénir (to bless). As a refresher for regular -ir verbs, you take the ils or elles form of the present indicative (ils bénissent), drop the -ent, and add the subjunctive endings. For le ciel (it), the ending is -e, giving us bénisse.

I usually translate le ciel as 'the sky'. How do I know it means 'heaven' here?

Context! While le ciel does mean 'the sky' in everyday weather or nature contexts, it is also the standard French word for 'heaven' in religious, poetic, or figurative contexts. The verb bénir (to bless) makes it obvious that we are talking about heaven in a spiritual sense.

Is there an invisible verb before Que in sentences like this?