The Hamsa said: 'Friend, I will declare unto you one foot of Brahman.' 'Declare it, Sir,' he replied. He said to him: 'Fire is one quarter, the sun is one quarter, the moon is one quarter, lightning is one quarter. This is a foot of Brahman, consisting of four quarters, and called Gyotishmat (full of light).

In plain words: The swan teaches him another part of Brahman. It is made of four lights: fire, the sun, the moon, and lightning. This part is called 'Full of Light.'