Narada Purana — Purva Bhaga, Shloka 23
The Exposition of the Dvādaśī Vow for the Twelve Months
Dvādaśī-vrata-nirṇaya and Mahā-dvādaśī Lakṣaṇas
व्रतेनानेन देवेशः श्रीधरः प्रीयतामिति । द्वादश्यां नभस्यशुक्ले व्रती संपूज्य वामनम् ॥ २३ ॥
vratenānena deveśaḥ śrīdharaḥ prīyatāmiti | dvādaśyāṃ nabhasyaśukle vratī saṃpūjya vāmanam || 23 ||
“愿室利陀罗——诸天之主——因这誓愿而欢喜。”如是，于那婆娑月白分第十二日，守愿者当如法礼拜供奉婆摩那（Vāmana）。
Narada (teaching in the Narada–Sanatkumara dialogue frame)
Vrata: Dvādaśī-vrata (Vāmana/Śrīdhara-pūjā; specific vrata-name not stated)
Primary Rasa: bhakti
Secondary Rasa: shanta
FAQs
It frames the vrata as an offering of devotion whose aim is Viṣṇu’s pleasure—specifically Śrīdhara—achieved through timely worship of Vāmana on an auspicious lunar day.
Bhakti is expressed here as intentional, time-bound worship: the devotee performs a vow and dedicates its merit to pleasing the Lord, focusing the mind on Viṣṇu in the form of Vāmana.
Kalā/astronomical timing (Jyotiṣa-based tithi observance) is implied: the rite is prescribed specifically for the bright-fortnight Dvādaśī in the month Nabhas, showing the ritual importance of correct lunar calendrics.