Now, in terms of the fifth resolve:

Great beings on this ground so Hard to Overcome
Cannot be conquered even by the demon hordes.

The Bodhisattvas dwelling on the fifth bodhisattva ground cannot be overcome even by the divine child-demons (devaputramāra) dwelling in all the realms of the world, let alone all other demons subservient to them. That is why this ground receives the name Hard to Conquer.

It should be recognised of the bodhisattvas that:

With excellent absorption these high-minded ones
Are masters in the subtle nature of the truths. (5.1)

Now, from among the ten perfections, it is the perfection of meditative absorption which is foremost. High-minded ones (sumati) is a reference to noble beings (ārya). Their truths are the truths of the high-minded, meaning the noble truths. Nature (svabhāva) refers to its true condition (svarūpa). The nature that is comprehended through exact understanding is the exact nature, and those who have a subtle understanding of the true condition of the truths of the high-minded are supremely wise. The four noble truths referred to here are those of suffering, origin, cessation and path.

But the Illustrious One taught that there are only two truths, namely the relative truth and the ultimate truth. As stated:

The knowers of the world themselves declared,
And not by hearsay, that there are two truths:
The relative and the ultimate.
There is no such thing as a third truth.¹

And from the Middle Way Treatise:

The dharma teachings of the buddhas
Are based on two truths:
The relative truth of the world
And the ultimate truth.²

Why then, it may be asked, do we have these four noble truths as distinct from the two truths? To explain we would say that, although that is indeed so, it is in order to separately indicate the causal and resultant aspects of what to adopt and what to reject that the four noble truths have been related in this manner. The aspect that needs to be rejected is thorough affliction (saṃkleśa), its result being the truth of suffering and its cause the truth of origin. The aspect that needs to be adopted is complete purification, its result being the truth of cessation and the cause for attaining this being the truth of the path. Among these, the truth of suffering, origin and path are included within the relative truth, while the truth of cessation is the essential condition of the ultimate truth. Any other truths, whatever they may be, would likewise certainly also be included within these two truths.

Are there then other truths different from the four truths? Yes, there are. As stated in the context of the fifth bodhisattva ground:

They know with complete accuracy that, ‘This is the noble truth of suffering’. They know with complete accuracy that, ‘This is the noble truth of the origin of suffering, the cessation of suffering, and the path leading to the cessation of suffering.’ They are well-versed in the relative truth, well-versed in the ultimate truth, well-versed in the truth of characteristics, well-versed in the truth of distinctions, well-versed in the truth of examination, well-versed in the truth of substance, well-versed in the truth of production, well-versed in the truth of knowing extinction and non-arising, well-versed in the truth of engaging with the knowledge of the path, and well-versed in the truth of mastering the progression through all the levels of the bodhisattva grounds culminating in the wisdom of a tathāgata.

Related to these, accurately satisfying the wishes of other sentient beings, they fully know the relative truth. Applying themselves accurately to the sole path, they fully know the ultimate truth. Having realised their own and the shared characteristics, they fully know the truth of characteristics. Having understood the principles of distinguishing dharmas, they fully know the truth of distinctions. Having experienced what harms body and mind, they fully know substances. Having realised the connections involved in migrating, they fully know rebirth. Having fully pacified all the torments of illness, they fully know extinction and non-arising. Having mastered non-duality, they fully know how to engage with the knowledge of the path. Having perfectly assimilated the knowledge of all aspects, they fully know the truth of achieving the connections up through all the levels of the bodhisattva grounds culminating in the wisdom of a tathāgata.³

This concludes the fifth resolve from the Commentary to Entering the Middle Way.