Dhanteras is celebrated on Ashvin/Aaso Vad 13, which marks the beginning of the five day long celebration of the Diwali festival. This day is also celebrated as Dhanvantari Triyodashi/Dhanvantari Jayanti.

Lord Dhanvantari is the 12th incarnation and one of the plenary portion of Purushottam Narayan (Amsh avatar). His advent is described within the 12th chapter of Vasudeva Mahatmya within the Vishnu Khanda of the Skanda Purana and also the 8th canto, 8th chapter, line(s) 31-34 of Shreemad Bhagwat Mahapurana.

The events described in the scriptures above relate to the churning of the milky ocean (Samudra Manthan) for elixir sought by the demi-gods and demons after Sage Durvasa’s curse upon Indra bereft the three worlds of wealth.

Various divine objects and beings emerged from the ocean during this process. Goddess Lakshmi was one of the divine beings making her appearance. Lord Dhanvantari appeared with a pot full of elixir. The purpose of His advent in the world was to teach men the science of Ayurveda.

In the Avatar Chintamani, composed by revered Nishkulanand Swami; he narrates as follows:

વળી ધન્વંતરી તન ધારી, ટાળ્યો રોગ આયુષ્ય વધારી, દીનબંધુ એ દીનદયાળુ, કર્યું સર્વ જગતને સુખાળું. ૨૨

Vadi Dhanvantari tan dhaari, taadyo rog, aayushya vadhaari, dinbandhu e dindayalu, karyu sarva jagat ne sukhaadu. 22

He incarnated as Dhanvantari (Divine Doctor) and averted diseases thus increasing life span || Friendly and compassionate to the poor, He comforted the Universe with this benediction (Knowledge of the Ayurveda/Science of Medicine). 22

On this day:

Lord Swaminarayan instructs His devotees to remember various pastimes of God/Lord in various incarnations as per the 3rd Vachanamrut of Gadhda Pratham Prakran.

Therefore, devotees remember the pastimes of Lord Dhanvantari - the One who is conversant with the science of medicine (Ayurveda) and the purpose of His advent.

Worship is also offered to Goddess Lakshmi as we express our gratitude for the wealth and prosperity she brings and also marking the day of her appearance as the daughter of the Ocean.

In previous era/ages one’s wealth was measured by the number of domesticated animals owned. Today, wealth is measured by money, cars and houses that one owns. Wealth that is earned through hard work and honesty abiding by the codes of conduct is blessed. Farmers and householders, who own cows and bullocks, decorate the horns of their animals with different colours and worship them.

Temples and homes are cleaned and rangoli designs are made, ghee lamps are lit to welcome Goddess Lakshmi who is the Goddess of fortune and proprietor of all opulences and also to welcome Lord Dhanvantari who brings good health and happiness in life.

Goddess Lakshmi (Maha-Lakshmi) makes her presence on earth and enters clean and bright homes hence devotees create such welcoming atmosphere as described above.

She is also our 2nd Guru (Spiritual Master) within the Spiritual Masters successorship

Devotional Hymns (Stotram and Kirtan):

Goddess Lakshmi is mostly worshipped with Sri Suktam which comes from the Rig Veda.

The 37th verse of this hymn ends in the following way:

Ya Evam Veda |

Om Mahaa-Devyai Ca Vidmahe Vishnu-Patnii Cha Dhiimahi | Tanno Lakssmiih Pracodayaat - Om Shaantih Shaantih Shaantih ||37||

The essence of Maha-Lakshmi, indeed is Veda - the ultimate knowledge.

May we know the divine essence of the great Goddess meditating upon Her, who is the consort of Shree Vishnu.

May that divine essence of Lakshmi awaken our spiritual consciousness.

Aum Peace Peace Peace. 

Note: The prayer above are from the Vedas and only the ones well versed in the knowledge of them can/are permitted to recite these mantras.

Devotees also recite the Shree MahaLakshmi Stotra, 11 verse hymn composed by Lord Indra (King of the heavenly planets). The 1st verses of this hymn is as follows:

Namastestu Mahaa-Maaye Shree-Peetthe Sura-Puujite |

Shankh-Chakra-Gadaa-Haste Mahaalakssmi Namostute ||1||

Salutations unto Goddess MahaLakshmi, to the great enchantress, worshipped by the demi-gods in Her abode, wielder of the Conch shell, Disc and Mace; Salutations unto that Maha-Lakshmi.

Note: The prayer above is Puranic (i.e. from the Purans) and can be recited by anyone upon learning it.

Various Nand Saints have composed Kirtans related to this auspicious day. One such is Bhramanand Swami, whose composition is as below and can be found in the Kirtan Sar Sangraha.

In a summary:

The ornaments that the Lord adorns and utensils used for the Lord’s worships should be properly washed and cleaned. The temple should be washed and cleaned, thereafter the Lord should be worshipped with a Tilak of Kumkum.

The Lord should be dressed in red cotton velvet clothing adorned with a piece of cloth woven with golden threads round the head. Goddess Lakshmi should be adorned with a green saree and ornaments. Food items such as Jalebi, Khaja (wheat flour sweet) should be offered to the Lord. Devotees of the Lord should sing devotional songs (Kirtans) related to the occasion and light ghee lamps throughout the three days until Diwali.

In the Vaishnava tradition, Lord is offered ghee lamps and seated within a decorated bungalow.