The cultus was probably similar to what may be seen in the Sivaite temples of India to-day. The principal lingam was placed in a shrine approached through other chambers and accessible only to privileged persons. Libations were poured over the emblem and sacred books were recited. An interesting inscription[292] of about 600 A.D. relates how Śrîsomasarman (probably a Brahman) presented to a temple "the Râmâyaṇa, the Purâṇa and complete Bhârata" and made arrangements for their recitation. Sanskrit literature was held in esteem. We are told that Sûryavarman I was versed in the Atharva-Veda and also in the Bhâshya, Kâvyas, the six Darśanas, and the Dharmaśâstras[293]. Sacrifices are also frequently mentioned and one inscription records the performance of a Koṭihoma[294]. The old Vedic ritual remained to some extent in practice, for no circumstances are more favourable to its survival than a wealthy court dominated by a powerful hierarchy. Such ceremonies were probably performed in the ample enclosures surrounding the temples[295].
Mahayanist Buddhism existed in Camboja during the whole of the period covered by the inscriptions, but it remained in such close alliance with Brahmanism that it is hard to say whether it should be regarded as a separate religion. The idea that the two systems were incompatible obviously never occurred to the writers of the inscriptions and Buddhism was not regarded as more distinct from Śivaism and Vishnuism than these from one another. It had nevertheless many fervent and generous, if not exclusive, admirers. The earliest record of its existence is a short inscription dating from the end of the sixth or beginning of the seventh century[296], which relates how a person called Pon Prajnâ Candra dedicated male and female slaves to the three Bodhisattvas, Śâstâ[297], Maitreya and Avalokiteśvara. The title given to the Bodhisattvas (Vrah Kamratâañ) which is also borne by Indian deities shows that this Buddhism was not very different from the Brahmanic cult of Camboja.
It is interesting to find that Yaśovarman founded in Angkor Thom a Saugatâśrama or Buddhist monastery parallel to his Brâhmaṇâśrama already described. Its inmates enjoyed the same privileges and had nearly the same rules and duties, being bound to afford sanctuary, maintain the destitute and perform funeral masses. It is laid down that an Acârya versed in Buddhist lore corresponds in rank to the Acâryas of the Śaivas and Pâsupatas and that in both institutions greater honour is to be shown to such Acâryas as also are learned in grammar. A Buddhist Acârya ought to be honoured a little less than a learned Brahman. Even in form the inscriptions recording the foundation of the two Aśramas show a remarkable parallelism. Both begin with two stanzas addressed to Śiva: then the Buddhist inscription inserts a stanza in honour of the Buddha who delivers from transmigration and gives nirvâṇa, and then the two texts are identical for several stanzas[298].