how vishnu became a dwarf

तृष्णे देवि नमस्तुभ्यं कृतकृत्यासि साम्प्रतम्।

अनतनाम यद्रूपम् तत्त्वया वामनीकृतम्॥

विद्यापतिप्रणीते पुरुषपरीक्षायाम्॥

tṛṣṇe devi namastubhyaṁ kṛtakṛtyāsi sāmpratam|

anatanāma yadrūpam tattvayā vāmanīkṛtam||

vidyāpatipraṇīte puruṣaparīkṣāyām||

The quote is from the work Purushapareeksha by the author Vidyapati.

------------------

The poet is trying to bring home the fact that when a person is intensely craving to get something, his stature, however lofty is would be reduced to dwarfish, Lilliputan dimensions in the presence of the one who is capable of fulfilling that craving either fully or partially.

Here the allusion is to the great incarnation of Vishnu as Vamana too.

To regain the lost kingdom of his elder brother Indra the leader of Gods from the chieftain of Asuras, Lord Vamana, Vishnu himself incarnate as a young dwarfish brahmin boy, visits the hallowed land in the banks of Narmada where King of Asuras, is conducting a great yajna or Sacrifice..

The Asura king, who is generous to a fault, offers almost anything for the the visiting dwarf..

The dwarf Vamana begs for just three measures of land with is feet, but when the gift is concluded, the dwarf grows into Trivikrama who pervades the whole universe.. The whole earth and other worlds are not large enough to cover even His two steps.. And the third step was placed on the head of Bali.. That is the story..

But the real form of Lord Vishnu is infinite.. and the poet says that he became dwarf becauase he felt so ashamed before the demon king when he begged for something..

Yes, when we approach someone for some favours, our stature, however tall, gets diminished..

The dwarf Vamana grew to Thrivikrama who pervaded the whole universe, just in form.

But the Lord had become dwarf for even when he begged..

So desire converted the Lord of Infinite glory to a dwarf..

And this exactly is the purpose for which desire, greed, avariciouness.. all are created..

===================

The meaning of the Slokam is

Oh Goddess desire and want, my pranams in utter supplication to you.. Now, You are the one who has achieved whatever you desired.

The form which is normally found as of infinite spread, has been reduced to a tiny dwarf by you.

======================

Analyasis

देवी तृष्णे तुभ्यं नमः I prostrate befor you, oh Goddess Desire,

साम्प्रतं now कृतकृत्या असि You have accomplished now what you wanted

यद्रूपं which form

अनन्तनाम is considered as of infinitely huge

तद् that form

त्वया by you

वामनीकृतं converted or reduced to a dwarf.