4-8

परित्राणाय साधूनाम् विनाशाय च दुष्कृताम् ।
धर्म सम्स्थापनार्थाय सम्भवामि युगे युगे ॥ ८ ॥

paritrANAya sAdhUnAm vinAzAya ca duSkRtAm |
dharma samsthApanArthAya sambhavAmi yuge yuge || 8 ||

सम्भवामि [sambhavAmi] I take birth युगे युगे [yuge yuge] in the various yugas परित्राणाय [paritrANAya] for the protection साधूनाम् [sAdhUnAm] of virtuous people, विनाशाय [vinAzAya] for the destruction दुष्कृताम् [duSkRtAm] of malice च धर्म सम्स्थापनार्थाय [ca dharma samsthApanArthAya] and to establish My principles.

Virtuous people are those who are inclined to stand for My principles, as described in the previous Shloka. They are called Vaishnavas and are the best among my followers. They exist in my refuge.

I form Myself, so that My followers can grasp and worship Me.

My name, actions and form cannot be expressed by speech or thought. Without seeing Me, My followers would neither carry their body nor nourish it. They feel that passing a moment without seeing Me is like the passing a thousand cycles of creation. They would lose strength in their limbs if they don’t see Me. I take birth to protect them, by showing Myself and by interacting with them. My birth is also to destroy those who are opposed to My followers.

To establish the principles laid down in the Vedas, I enable people to worship Me by showing Myself in a form that can be worshipped.

To accomplish these goals, I create Myself over the ages in the form of a human, a power or even something else.

In this Shloka, the phrase ‘various yugas’ conveys the meaning that the Lord has no preference for any particular yuga , such as कृत [kRta] or त्रेत [treta]