Why Do We Offer Water on the Shivling on Monday?
To cool Shiva down. When Mahadev held the halahala poison from the churning of the ocean in his throat, his body began to burn — the gods poured water to cool him, and that became jalabhishek. Monday, because 'Som' means the Moon, who sits on Shiva's head; the day is counted as his. Water is the plainest offering — Shiva is Ashutosh, easily pleased.
The Monday jalabhishek rests on one idea — cooling the burn. In the story of the churning of the ocean by the devas and asuras, the first thing to surface was the halahala poison, whose heat began to scorch all three worlds. Shiva drank it and held it in his throat, which is why he is called Neelkanth, the blue-throated one. The episode is found in the eighth canto of the Bhagavata Mahapurana.
Why the gods poured water
The poison's heat set Shiva's body burning, so the gods poured an unbroken stream of water over him — this part is popular telling, not a quoted line from the Bhagavata. The devotee today is repeating the same act: a thin, continuous stream, so the coolness holds. Reading it as a rule with a threat attached ("do this or something bad will happen") gets it wrong; it is a tradition of feeling, not fear.
Why Monday
'Som' is a name for Chandra, the Moon, and the Moon sits on Shiva's head — which is why he is Chandrashekhar. The Shiva Purana tells that Chandra, waning under Daksha's curse, worshipped Shiva at Prabhas and found relief; that place is Somnath today, counted first among the twelve jyotirlingas. Tradition also reads 'Som' as 'sa-Uma' — Shiva together with Uma. The Mondays of Shravan and the Solah Somvar vrat sit at the centre of Shiva bhakti for the same reason.
Water, milk and the regional difference
Tradition calls Shiva 'abhishek-priya' — he takes to the stream, not the decoration. In North India plain water or Gangajal is the mainstay; this is what kanwariyas carry in Shravan. Many households mix a little raw milk into the water. In South Indian temples, abhishekam with panchamrit — milk, curd, ghee, honey, sugar — and coconut water is more common. Even in Rudrabhishek the rule is that panchamrit is followed by plain water at the end. Milk is an option, not a requirement.
What people usually get wrong
- Milk is not compulsory — an abhishek done with water alone is not considered incomplete.
- The tradition is a slow, steady stream, not a pot emptied in one go.
- The parikrama goes up to the jaladhari (somasutra) and back, not across it.
- Jalabhishek is not a Monday-only rule — Monday is simply when it is held to matter most.
Many people chant the Mahamrityunjaya mantra while doing abhishek — "ॐ त्र्यम्बकं यजामहे सुगन्धिं पुष्टिवर्धनम्। उर्वारुकमिव बन्धनान् मृत्योर्मुक्षीय मामृतात्॥" It is from the Rigveda (7.59.12). Plainly: we worship the three-eyed, fragrant Shiva who nourishes; as a ripe cucumber slips free of its stem, may we be released from the bondage of death — not from immortality.