The story of why विष्णु is called श्रीवत्सलाञ्छन is narrated in भागवत पुराण at Skandha 10, Adhyaya 89 as follows: (Taken from
१०८९००१० श्रीशुक उवाच
१०८९००११ सरस्वत्यास्तटे राजन्नृषयः सत्रमासत
१०८९००१३ वितर्कः समभूत्तेषां त्रिष्वधीशेषु को महान्
१०८९००२१ तस्य जिज्ञासया ते वै भृगुं ब्रह्मसुतं नृप
१०८९००२३ तज्ज्ञप्त्यै प्रेषयामासुः सोऽभ्जगाद्ब्रह्मणः सभाम्
१०८९००३१ न तस्मै प्रह्वणं स्तोत्रं चक्रे सत्त्वपरीक्षया
१०८९००३३ तस्मै चुक्रोध भगवान्प्रज्वलन्स्वेन तेजसा
१०८९००४१ स आत्मन्युत्थितम्मन्युमात्मजायात्मना प्रभुः
१०८९००४३ अशीशमद्यथा वह्निं स्वयोन्या वारिणात्मभूः
१०८९००५१ ततः कैलासमगमत्स तं देवो महेश्वरः
१०८९००५३ परिरब्धुं समारेभ उत्थाय भ्रातरं मुदा
१०८९००६१ नैच्छत्त्वमस्युत्पथग इति देवश्चुकोप ह
१०८९००६३ शूलमुद्यम्य तं हन्तुमारेभे तिग्मलोचनः
१०८९००७१ पतित्वा पादयोर्देवी सान्त्वयामास तं गिरा
१०८९००७३ अथो जगाम वैकुण्ठं यत्र देवो जनार्दनः
१०८९००८१ शयानं श्रिय उत्सङ्गे पदा वक्षस्यताडयत्
१०८९००८३ तत उत्थाय भगवान्सह लक्ष्म्या सतां गतिः
१०८९००९१ स्वतल्पादवरुह्याथ ननाम शिरसा मुनिम्
१०८९००९३ आह ते स्वागतं ब्रह्मन्निषीदात्रासने क्षणम्
१०८९००९५ अजानतामागतान्वः क्षन्तुमर्हथ नः प्रभो
१०८९०१०१ पुनीहि सहलोकं मां लोकपालांश्च मद्गतान्
१०८९०१०३ पादोदकेन भवतस्तीर्थानां तीर्थकारिणा
१०८९०१११ अद्याहं भगवंल्लक्ष्म्या आसमेकान्तभाजनम्
१०८९०११३ वत्स्यत्युरसि मे भूतिर्भवत्पादहतांहसः
The English version of the same story at
this website is as follows:
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Once, long ago, on the shore of the river Sarasvati, a discussion arose among a group of sages as to which of the three chief lords-Brahmā, Vishnu or Shiva-is the greatest. They deputed Bhrigu Muni to investigate the matter.
Bhrigu decided to test the lords’ tolerance, for that quality is a sure sign of greatness. First he entered the court of Lord Brahmā, his father, without offering him any respect. This enraged Brahmā, who suppressed his anger because Bhrigu was his son. Next Bhrigu went to Lord Shiva, his older brother, who rose from his seat to embrace him. But Bhrigu rejected the embrace, calling Shiva a deviant heretic. Just as Shiva was about to kill Bhrigu with his trident, Goddess Pārvati interceded and pacified her husband. Next Bhrigu went to Vaikuntha to test Lord Nārāyana. Going up to the Lord, who was lying with His head on the lap of the goddess of fortune, Bhrigu kicked His chest. But instead of becoming angry, both the Lord and His consort stood up and offered Bhrigu respects. “Welcome,” said the Lord. “Please sit down and rest awhile. Kindly forgive us, dear master, for not noticing your arrival.” When Bhrigu went back to the assembly of sages and told them all that had happened, they concluded that Lord Vishnu is certainly supreme.
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Arvind Kolhatkar.