Mangalacharana

A mangalacharana (मङ्गलाचरणम्) or a mangalashloka is a benedictory verse traditionally featured in the beginning of a Hindu text. Composed in the form of an encomium, a mangalacharana serves both as an invocation and a panegyric to an author's favoured deity, teacher, or patron, intended to induce auspiciousness (maṅgalam). The verse may also be in the form of a divine supplication for the removal of obstacles that might obstruct the completion of the work.

The mangalacharana is a common convention in works of Hindu philosophy, beginning and sometimes also ending with the invocation of a deity. It is sometimes regarded to contain the essence of a given text to which it belongs.

Bhagavata Purana
The mangalacharana of the Bhagavata Purana addresses Krishna: "oṁ namo bhagavate vāsudevāya janmādy asya yato ’nvayād itarataś cārtheṣv abhijñaḥ svarāṭ tene brahma hṛdā ya ādi-kavaye muhyanti yat sūrayaḥ tejo-vāri-mṛdāṁ yathā vinimayo yatra tri-sargo ’mṛṣā dhāmnā svena sadā nirasta-kuhakaṁ satyaṁ paraṁ dhīmahi"

Mahabharata
The mangalacharana of the Mahabharata, also featured in the Bhagavata Purana, invokes Narayana (Vishnu), the sages Nara-Narayana, Saraswati, and Vyasa: "nārāyaṇaṁ namaskṛtya naraṁ caiva narottamam devīṁ sarasvatīṁ vyāsaṁtato jayam udīrayet"

Vishnu Purana
The mangalacharana of the Vishnu Purana propitiates Vishnu:

"om namo bhagavate vāsudevāya om jitam te puṇḍarīkākṣa namaste viśvabhāvana namaste 'stu hṛṣīkeśa mahāpuruṣa pūrvaja"