yadaa yadaa hi dharmasya glaanirbhavati bhaarata |
abhyutthaanamadharmasya tadaatmaanam srijaamyaham || 7 || 

Whenever there is a decline in righteousness, and a rise in unrighteousness prevails, then do I manifest myself, O Bhaarata.

yadaa yadaa hi: whenever
dharmasya : righteousness
glaanih : decline
bhavati : prevails
bhaarata: O Bhaarata
abhyutthaanam : rise
adharmasya : unrighteousness
tadaa : then
aatmaanam : myself
srijaami : manifest
aham : I

Shri Krishna described the process of Ishvara’s descent or avataara in the previous shloka. Here he speaks about the reason for manifesting as an avataara. He says that whenever there is a decay in dharma, and a rise in adharma, during that time he manifests himself in a particular form in this world. Now dharma means righteousness, but it also means universal harmony. Adharma then becomes disharmony.

Again, let us take the example of our body. Every cell and organ is working for the totality of the human being. It is the spirit of “one for all and all for one”, which is nothing but the spirit of yajna that we saw earlier. Our heart keeps beating and doesn’t ask for any reward or recognition. It just works for the sake of totality.

But sometimes, a part of the body, or the whole body, undergoes a situation when something goes wrong. Then, the intelligence of the body manifests itself to take care of the situation. If the problem is in one part of the body then special enzymes are secreted to remedy the situation, and white blood cells fight off the invaders. If the problem is in the whole body then it becomes warm under fever in order to get rid of intruders.

Similarly Ishvara comes either for short time like the Narasimha avataara, or for a long time like Shri Krishna avataar. Sometimes we find that the entire population thinks the same thought – e.g. an independence struggle or a social movement. That is also an avataara. If we go on polluting the environment with chemicals and so on, there could be a natural disaster in response. That is also an avataara .