Durga Puja begins through Mahalaya
According to Hindu mythology, Mahalaya marks the descent of Durga to the mortal realm.

Mahalaya, which marks the beginning of the Hindu community's largest religious festival, Durga Puja, is being observed across the country amid festivity today (21 September).
From early morning, temples resonated with Chandipath, tarpan rituals and devotional hymns in praise of the goddess Durga. The serene autumn dawn ushered in Devipaksha, the fortnight dedicated to the goddess, through the traditional recitation of sacred verses.
According to Hindu mythology, Mahalaya carries the significance of the descent of the goddess to the mortal realm. It is not only the formal beginning of the festivities but also a deeply spiritual occasion for devotees.
From this day, the countdown to Durga Puja begins. This year, Shashthi Puja will be celebrated on 28 September and Bijoya Dashami on 2 October, which will mark the goddess's departure to Kailash.
Scriptures mention three major milestones of Durga Puja: Mahalaya, Bodhon and Sandhi Puja. On Mahalaya, Durga receives the divine mandate to defeat the demon king Mahishasura.
Empowered by the combined forces of Brahma, Vishnu and Shiva, she emerges as "Mahashakti," adorned with 10 weapons and riding a lion, ultimately slaying Mahishasura after a nine-day battle.