infinite mercy of Krishna is His crowning glory

निष्कम्पे नित्यपूर्ण्णे निरवधिपरमानन्दपीयूषरूपे

निर्लीनानेकमुक्तावलिसुभगतमे निर्मलब्रह्मसिन्धौ।

कल्लोलोल्लासतुल्यं खलु विमलतरं सत्त्वमाहुस्तदात्मा

कस्मान्नो निष्कळत्वम् सकळ इति वचस्त्वत्कलास्वेव भूमन्॥४॥

श्रीमन्नारायणीये  दशकं॥१॥

niṣkampe nityapūrṇṇe niravadhiparamānandapīyūṣarūpe

nirlīnāneekamuktāvalisubhagatame nirmalabrahmasindhau|

kallolollāsatulyaṁ khalu vimalataraṁ sattvamāhustadātmā

kasmānno niṣkaḻatvam sakaḻa iti vacastvatkalāsveva bhūman||4||

śrīmannārāyaṇīye  daśakaṁ  ||1||

The quality of the sattwam.. the most exalted and the purest of the qualities, is eternally still and all pervasive, is remaining in the form of the sea of eternal ecstacy, and since innumerable blessed souls have already submerged in such sea, it is the most covetable one..and  the learned  seers say that the manifest satwa guna is only the gentle ripplelikes waves in the ocean of Brhmam which is exclusively manifested as sudhdhasatwa.. You are the manifestation of such motionless formless sattwa  and you are indeed formless but for the benefit of us you have appeared before us exhibiting sacred and divne signs,  you  who pervade the whole word is appearing as a deity in a limited idol for the benefit of the lucky devotees.

The description is rather abstract.  The brhman that is guruvayurappan is only an all pervasive manifestion of sattwaguna and he can very well choose to be aatmaarama (just contemplating in ones own exalted state and enjoy the ecstacy)  but He has manifested himself with some divine signs on this earth for the benefit of us, the lucky ones.   The infinite mercy of Krishna is His crowning  glory.. only  because of that mercy he has chosen to appear in guruvaayuur.  Devotees, never miss a chance to see Him there.