Aśvattha (Aswattha) is one of the trees that have been considered as ‘divine trees’. In Vibhūtiyoga (Vibhutiyoga) of Bhagavadgītā (Bhagavadgita), while describing his manifestation as the Supreme God, Śrī Kṛṣṇa (Sri Krishna) has identified all things greatest in this world, as manifestation of His own Self. In this context he says, I am Aśvattha among trees —
aśvatthaḥ sarvavṛkṣāṇām.

From the mention of Aśvattha in Bhagavadgītā as the vibhūti (vibhuti, attributes of divine glory)of God, it is clear that the religious status of this tree was held in high esteem. Since the period of Ṛgveda (Rigveda), the greatness of the Aśvattha tree had been in discussion, and in modern India, too, trees like vaṭa (vata, banyan) and aśvattha are well-respected by the common people. Botanists have also kept in mind this religious status of the aśvattha tree. The Latin name of this tree is Ficus religiosa. This nomenclature itself reflects the religious significance of the tree.

Another name of aśvattha is ‘pippala’. Today, the name ‘pīpala’ is widely used, alongside aśvattha, especially in Hindi-speaking belts of India. However, both ‘aśvattha’ and pīpala’ had earliest mentions in Ṛgveda. In Ṛgveda and the later Upaniṣad(s) (Upanishad), in a famous śloka, Jīvātmā and Paramātmā have been compared to two birds sitting on the bough  of a(n) aśvattha or pippala tree —

dvā suparṇa sayujā sakhāyā samanaṃ vṛkṣaṃ pariṣasvajāte
tayoraṇyaḥ pippalaṃ svādvattyanaśnanno’bhicākaśīti.

this pippala or aśvattha is like the universe, and Jīvātmā (Jivatma, the living being’s soul)and Paramātmā (Paramatma; the Supreme Self)  perch on its two branches, like two birds. Jīvātmā partakes of its fruit, that is, enjoys karmaphala (fruit of action) and the other, Paramātmā, looks on as mere witness.

This conception of Aśvattha as the universe, as described in Vedic texts and Upaniṣad(s), can be found in a summarised form in Mahābhārata (Mahabharata), in a śloka (sloka; verse) of Bhagavadgītā. It is said there — saṃsāra(samsara; the mortal world) is a tree like Aśvattha, whose roots are heading upwards, and branches face downwards. This tree is without decline, and the Vedamantra(s) are its branches and twigs. One who properly knows this tree-like saṃsāra, is the true knower of Veda–
ūrdhvamūlamadhaḥ śākham aśvatthaṃ prāhuravyayam
chandāṃsi yasya parṇani yastaṃ veda sa vedavit.

This concept of Bhagavadgītā is supported by a śloka of Kaṭhopaniṣad (Kathopanishad). There the reading goes as ‘ūrdhvamūlo’vākśākha’ —
ūrdhvamūlo’vākśākha’ eṣo’śvatthaḥ sanātanaḥ
tadeva śukraṃ tadbrahma tadevāmṛtamucyate.

The upward-going roots of Aśvattha, as described in Bhagavadgītā and Kaṭhopaniṣad, is actually conceived as the supreme foothold of Brahman —
ūrdhvaṃ mūlaṃ yat tadviṣṇoḥ paramaṃ padamasyeti (Śānkarabhāṣya).
The Supreme God is conceptualised as the root of this Aśvattha tree, because he is the basis of cause of the creation of the whole universe. And the downward-moving branches of the tree of saṃsāra are representative of this finite world. Even if the branches are cut off, the root remains intact, and from that root, the tree can extend new branches. So, Brahman or the Supreme God is also without decline. At the time of Pralay (the great doomsday) a, when the whole universe is destroyed, Brahman remains the same and unaffected. After the great doom, it is from the Brahman that the creation takes shape anew. So, the one who is not ensnared by the illusions of this transient world, and is able to know the roots and branches of the tree of saṃsāra, is a true scholar of Veda.
The seed of this philosophical conception lies in the name ‘Aśvattha’ itself. ‘Śva’ means tomorrow, or the time afterwards. That which lasts till tomorrow, or the future time, is Aśvattha. The tree which lives for a long time, beyond measurement, is Aśvattha. The concept of Upaniṣad is a bit different. Here the branches of the tree are conceptualised as the mortal world. So the tree of Saṃsāra is imagined as Aśvattha. Just as the Supreme God starts the creation anew, so it is not known to common people that after the destruction of the tree, whether its branches would be created anew, out of its widespread roots. So the tree is called Aśvattha.

This Brahman-conception of Aśvattha can also be found in Mahābhārata. Two forms of the Supreme God — Viṣṇu (Vishnu) and Śiva (Siva)are both addressed in Mahābhārata as ‘Aśvattha’. In Vanaparva, the name ‘Aśvattha’ is found as as one of the hundred and eight names of Sūrya.

Since the Vedic ages, the attribution of the entire universe upon the Aśvattha tree has established him as a tree to be worshipped and respected. In Mahākāvya and Purāṇa(s), there are mentions of the Aśvattha tree established in several sites of pilgrimage. In Bhāgavatapurāṇa it is said that after the destruction of Yaduvaṃśa (Yaduvamsa; the lineage of Yadu), deciding to leave this mortal world, Kṛṣṇa sat down in a mood of dejection under a(n) Aśwattha tree, and there he met his death when a hunter called Jarā struck him with an arrow.