B.G 4.13

चातुर्वर्ण्यं मया सृष्टं गुणकर्मविभागशः। तस्य कर्तारमपि मां विद्ध्यकर्तारमव्ययम् ॥१३॥

The classification system of four classes, based on the duties to be performed according to one's qualities, is created by Me. Even though I am the creator of these, know Me as the non-doer, and as imperishable.

Gīta Tātparya 4.13

Only those who are of 'sātwik' quality are Vaishnavas, i.e. devotees of lord Vishnu. The varna classification based on birth is merely indicative based on the number of 'sātwik' devotees found. Vaishnavas are found in all classes, and the apparent differences eventually dissolve as per the inherent nature. Divisions based on the action is stated at verse 18.42 of Gita. The word 'api' referenced regarding a combination of qualities is to be understood to mean 'none creates Me'.

"सत्वसत्वाधिकरजोरजोभिस्तमसा तथा। वर्णा विभक्ताश्चत्वारः सात्विका एव वैष्णवा॥" ]

"From 'satwa' quality comes goodness, from 'rajas' comes excess of passion, and from 'tamas' comes in the same way (darkness). Thus are the classification of the varnas into four. Only those who are of 'sātwik' quality are Vaishnavas, i.e. devotees of lord Vishnu.

इति च।

-stated thus.

कर्मविभागं "शमो दम" इत्यादिना वक्ष्यति।

Divisions based on the action is stated at verse "śamo dama" (18.42), and onwards.

"वैष्णवाः सात्विका एव तामसा एव चापरे। दौर्लभ्यसुलभत्वेन तेषां वर्णादिभिन्नता॥"

Indeed, the Vaishnavas, i.e. followers of lord Vishnu, are of Sātwik quality. Based on their ease of availability and rarity, they are classified into varnas.

इति च।

-stated thus as well.

"स्वाभाविको ब्राह्मणादिः शमाद्यैरेव भिद्यते। योनिभेदकृतो भेदो ज्ञेय औपाधिकस्त्वयम्। विष्णुभक्तिश्चानुगता सर्ववर्णेषु विश्पतिम्। आरभ्य हीयतेऽथापि भेदः स्वाभाविकस्ततः॥"

"The Brahmin and others are distinguished solely by qualities such as control of senses. The difference caused by distinctions in birth should be understood as merely attributive. Devotion to Vishnu, the lord of all, is to be found in all varnas. Even though distinctions may arise (because of birth), they eventually dissolve as per the inherent nature."

इति नारदीये।

-sates Naradiya Purana.

"कर्तापि भगवान् विष्णुरकर्तेति च कथ्यते। तस्य कर्ता यतो नान्यः स्वतन्त्रत्वात् परात्मनः॥"

"The lord Vishnu is spoken of as 'non-doer' even though He is the doer. As that supreme being is independent, He is non different from his acts."

इति च।

- stated thus as well by the testimonial.

अपिशब्दो गुणसमुच्चयार्थः। कर्ता मे नास्तीत्यपि विद्धीति ॥१३॥

The term 'api', i.e. 'even', is referenced regarding a combination of qualities. It is to be understood to mean 'none creates Me'.