Neither a god nor a gandharva, nor Māra together with Brahma could make such a being lose their victory.

Neva devo na gandhabbo — neither a god nor a gandharva: deva are the gods of the Buddhist pantheon. gandhabba are celestial beings, musicians of heaven. Powerful beings but inferior to the arahant in terms of realization.

Na māro saha brahmunā — nor Māra together with Brahma: the lord of death and illusion together with the supreme divinity of the Brahmanic pantheon. The combination of the two most powerful forces in the cosmos could not break the inner victory.

Jitaṃ apajitaṃ kayirā — make them lose their victory: apajita is the opposite of jita. Victory over oneself, once genuinely achieved, is irrevocable. This is the Buddhist doctrine of irreversibility of path states.

This verse completes the trilogy of the great inner conquest: more valuable than a thousand battles (103), more stable than any conquest of others (104), invulnerable even to cosmic powers (105).