Shri Krishna says that a truly wise and self-realized individual perceives the same divine essence in all beings, regardless of their external differences. This understanding is rooted in various spiritual teachings and scriptures. 

Just as the ocean views all its waves as one, and gold sees no difference in various ornaments made from it, the wise see the same divine essence in all beings. Lord Krishna explains that a self-realized soul sees the same divine presence in all creatures, be it a Brahmin, an elephant, a dog, or even an outcast.

Let us take the example of water, ice and steam. Now imagine you come across some people who are debating and fighting over which is superior of the three. Some say water is superior, some say steam is superior while some say ice is superior. What will you tell them? A learned person can see that all three are basically just different forms of the same water molecule H2O. In normal state, H2O is liquid water, in condensed state it is ice and in expanded state it is steam. 

Just like that, Krishna is saying that vidyā vinaya sampanne, people with knowledge and humility can see that all living beings, regardless of whether they are brahmins, shudras, cows, dogs, etc are all tiny parts of the same supreme God. In verse 5.18, Shri Krishna calls this the ‘vision of knowledge’. Please note that Krishna keeps reiterating the importance of humility while gaining knowledge. According to Krishna, humility is the first sign of possessing true knowledge. Humility is a very important quality of a vaishnava as per Krishna and the same thing has also been reiterated by lord Chaitanya.