In plain words
This body is a body made of clay. They came to recognise the truth that in this vessel of clay dwells Divinity, made of pure consciousness. They went on giving Him the name Hiraṇyagarbha. So in this way, from the very first, the human being went on advancing little by little, and at the last went on gaining the Divinity that recognises oneness. They also went on creating another name for Him. They called Him Īśvaraḥ. That is, the One who possesses all wealth. What is this wealth? Money is one kind of wealth. Health too is a kind of wealth. Learning is a wealth. Good character is a wealth. Intelligence is a wealth. They went on counting everything as a kind of wealth. All of these are wealth of one kind or another. They came down to the truth that Īśvara is the embodiment of all wealth. Īśvara is the embodiment of all wealth.
Then, recognising the secret within this, they went on calling Him Śivaḥ. Śivaḥ means the One who is free of the three guṇas. He is beyond the guṇas of sattva, rajas and tamas. Since He is without guṇas, they also went on calling Him Śuddhasattva. That Śuddhasattva Himself is Śiva. That is the auspicious principle. It is only when there are no guṇas that auspiciousness comes about. It is when guṇas are present that inauspiciousness comes about. So Śivaḥ means the embodiment of auspiciousness. Little by little the human being went on rising to a still higher level. They went on giving Him the name Sambhavaḥ. What does Sambhava mean? The One who, by His own will and bound by no rule, has the resolve to come forth whenever He is needed, wherever He is needed, in whatever age He is needed: Him they called Sambhavaḥ. That is why, in the Bhagavad Gītā too:
Whenever there is a decline of Dharma, O Bhārata, and a rise of adharma, then I bring Myself forth. To protect the good and to destroy the evil-doers, to establish Dharma firmly, I come into being age after age.
Wherever He is needed, there He keeps coming forth. Because He has such freedom, they gave Him the name Sambhavaḥ. So in this way, holding to the inner meaning of each, they went on giving Him names. They gave Him another name, Īśa.
Īśa, Girīśa, Nareśa, Pareśa, Sureśa, Lord adorned with the serpent Śeṣa, Sāmba Sadāśiva, Śambhu, Śaṅkara, my refuge is the pair of Your feet.