vadanti tat tattva-vidas tattvam yaj jnanam advayam
brahmeti paramatmeti bhagavan iti sabdyate
 

"The Absolute Truth is realized in three phases of understanding by the knower of the Absolute Truth, and all of them are identical. Such phases of the Absolute Truth are expressed as Brahman, Paramatma, and Bhagavan." (Bhag. 1.2.11) These three divine aspects can be explained by the example of the sun, which also has three different aspects, namely the sunshine, the sun's surface and the sun planet itself. One who studies the sunshine only is the preliminary student. One who understands the sun's surface is further advanced. And one who can enter into the sun planet is the highest. Ordinary students who are satisfied by simply understanding the sunshine--its universal pervasiveness and the glaring effulgence of its impersonal nature--may be compared to those who can realize only the Brahman feature of the Absolute Truth. The student who has advanced still further can know the sun disc, which is compared to knowledge of the Paramatma feature of the Absolute Truth. And the student who can enter into the heart of the sun planet is compared to those who realize the personal features of the Supreme Absolute Truth. Therefore, the bhaktas, or the transcendentalists who have realized the Bhagavan feature of the Absolute Truth, are the topmost transcendentalists, although all students who are engaged in the study of the Absolute Truth are engaged in the same subject matter. The sunshine, the sun disc and the inner affairs of the sun planet cannot be separated from one another, and yet the students of the three different phases are not in the same category.
The Sanskrit word bhagavan is explained by the great authority, Parasara Muni, the father of Vyasadeva. The Supreme Personality who possesses all riches, all strength, all fame, all beauty, all knowledge and all renunciation is called Bhagavan. There are many persons who are very rich, very powerful, very beautiful, very famous, very learned, and very much detached, but no one can claim that he possesses all riches, all strength, etc., entirely. Only Krsna can claim this because He is the Supreme Personality of Godhead. No living entity, including Brahma, Lord Siva, or Narayana, can possess opulences as fully as Krsna. Therefore it is concluded in the Brahma-samhita by Lord Brahma himself that Lord Krsna is the Supreme Personality of Godhead. No one is equal to or above Him. He is the primeval Lord, or Bhagavan, known as Govinda, and He is the supreme cause of all causes.
 

isvarah paramah krsnah sac-cid-ananda-vigrahah
anadir adir govindah sarva-karana-karanam
 

"There are many personalities possessing the qualities of Bhagavan, but Krsna is the supreme because none can excel Him. He is the Supreme Person, and His body is eternal, full of knowledge and bliss. He is the primeval Lord Govinda and the cause of all causes." (Brahma-samhita 5.1)
In the Bhagavatam also there is a list of many incarnations of the Supreme Personality of Godhead, but Krsna is described as the original Personality of Godhead, from whom many, many incarnations and Personalities of Godhead expand:
 

ete camsa-kalah pumsah krsnas tu bhagavan svayam
indrari-vyakulam lokam mrdayanti yuge yuge
 

"All the lists of the incarnations of Godhead submitted herewith are either plenary expansions or parts of the plenary expansions of the Supreme Godhead, but Krsna is the Supreme Personality of Godhead Himself." (Bhag. 1.3.28)
Therefore, Krsna is the original Supreme Personality of Godhead, the Absolute Truth, the source of both the Supersoul and the impersonal Brahman.
In the presence of the Supreme Personality of Godhead, Arjuna's lamentation for his kinsmen is certainly unbecoming, and therefore Krsna expressed His surprise with the word kutas, "wherefrom." Such unmanly sentiments were never expected from a person belonging to the civilized class of men known as Aryans. The word Aryan is applicable to persons who know the value of life and have a civilization based on spiritual realization. Persons who are led by the material conception of life do not know that the aim of life is realization of the Absolute Truth, Visnu, or Bhagavan, and they are captivated by the external features of the material world, and therefore they do not know what liberation is. Persons who have no knowledge of liberation from material bondage are called non-Aryans. Although Arjuna was a ksatriya, he was deviating from his prescribed duties by declining to fight. This act of cowardice is described as befitting the non-Aryans. Such deviation from duty does not help one in the progress of spiritual life, nor does it even give one the opportunity to become famous in this world. Lord Krsna did not approve of the so-called compassion of Arjuna for his kinsmen.