Śrīmad-Bhāgavatam 1.3.31

It is further confirmed herein that with our material eyes and senses we cannot see the Lord, who is all spirit. We cannot even detect the spiritual spark which exists within the material body of the living being. We look to the outward covering of the body or subtle mind of the living being, but we cannot see the spiritual spark within the body. So we have to accept the living being's presence by the presence of his gross body. Similarly, those who want to see the Lord with their present material eyes or with the material senses are advised to meditate on the gigantic external feature called the virāṭ-rūpa. For instance, when a particular gentleman goes in his car, which can be seen very easily, we identify the car with the man within the car. When the President goes out in his particular car, we say, "There is the President." For the time being we identify the car with the President. Similarly, less intelligent men who want to see God immediately without necessary qualification are shown first the gigantic material cosmos as the form of the Lord, although the Lord is within and without. The clouds in the sky and the blue of the sky are better appreciated in this connection. Although the bluish tint of the sky and the sky itself are different, we conceive of the color of the sky as blue. But that is a general conception for the laymen only.