This answer says that:
in terms of wisdom, a Hinayana arhat is more powerful than a bodhisattva before the 8th bhumi, because he abandoned afflictive obscurations while the bodhisattva abandons them from the 8th ground.
Is there a sutra (if not, a commentary) where I can read more about this?
The following quotes come from Shantideva's Bodhisattvacaryavatara as well as Maitreya's text on Buddha nature, and commentaries from Geshe Jamphel Gyaltsen.
In his commentary to Shantideva, verse 1, Geshe Jamphel Gyaltsen says:
Compared with an arhat (foe destryer) the omniscience of a buddha is higher. This is because only the mind of a buddha has the ability to perceive the two truths (conventional truth and ultimate truth) simultaneously. The mind of a Hinayana arhat does not have that capacity.
In Maitreya’s Sublime Continuum: The Essence of a One Gone Thus, with Commentary by Gyaltsap Darma Rinchen, it says:
The definition of a Sangha Jewel is an arya being endowed with any of the 8 qualities of knowledge and freedom, such as the knowledge of the mode of phenomena.
Geshe Gyaltsen commentary reads:
We do not need all eight to be a Sangha Jewel. The last set of three are qualities of true cessation and an arya bodhisattva on the first uninterrupted path of the path of seeing doesn’t yet have true cessations in his continuum and therefore not those last four qualities related to freedom. The arya bodhisattva mentioned in the Uttaratantra is of the eighth ground/bumi upwards and this arya has abandoned all afflicted obstructions so they have the freedom of those afflictive obstructions but not of the knowledge obstructions, since only a buddha is free from them, but they are still called a Sangha Jewel. Therefore it is mentioned: any of those eight qualities.
With respect to the verse 72, "Qualities of the non-returner", the commentary is:
The bodhisattva who is a non-returner goes to complete enlightenment with no return—it is irreversible. This is the bodhisattva from the eighth bumi on, and includes the ninth and tenth bumis.
And:
The Sangha free from afflictive obstructions are the bodhisattvas from the eighth bhumi onwards. Before the eighth ground bodhisattvas still have the afflictive obstructions. This presentation is from the Prasangika Madhyamika point of view, who say that only from the eighth ground onwards the afflictive obstructions have been abandoned.
And:
Why do the Hinayana arhats not have the indivisible four qualities of the Buddha, the non-abiding or ultimate, final nirvana? It is because they do not have the causes or the bases to achieve the ultimate nirvana that are produced at the time of the three pure bumis. Without producing causes, no results arise and therefore these Hinayana arhats are said to be far from the final nirvana. And: The Hinayana arhats have some level of purity but no perfection of purity and even the bodhisattva from eighth ground up still has the obstructions of omniscience and therefore the purity is not complete. To attain that perfection of purity of a buddha we first need the devotion to the Mahayana because only by way of the Mahayana path we can abandon both obstructions. A Hinayana practitioner with only renunciation [and no bodhicitta] who follows the Hinayana path will only abandon among the two types of obstructions the afflictive obstructions and will not attain the purity free from both obstructions.
In addition, Madhyamika Prasangika posit that the two vehicles are not differentiated in terms of wisdom because they both realize the same object. At times, we say that the wisdom of a bodhisattva has a greater capacity because (1) it realized emptiness by way of relying on countless reasonings while that of so-called Hinayana do not, and (2) it is conjoined with bodhicitta, whih makes it more powerful. We say that the wisdom is like an axe, and bodhicitta like a strong arm. Without a strong arm, one cannot uproot a tree even if he possesses the axe.
