Why did Lord Ram banish Ma Sita?

Lakshman had just left Sita in the banks of river Ganga and travelling back to Ayodya, after explaining Her the cruel order he had been asked to execute by his emperor Ram, of banishing Sita. He was visibly grieve struck. Minister of Ikshvaku clan, Sumantra, who had accompanied Lakshman in had never seen Lakshman grieve so much for anything in life.

Moved by Lakshman's grief, minister Sumantra decided to reveal a celestial secret.

Oh Lakshmana, I have never seen you grieve so much for anything in life. What has happened to you? Why do you have to grieve for something that's a part of something predecided?

Respected Sumantra, I don't understand a bit of what you just said. Could you be clearer so that I can understand? I am indeed all lost and there is no peace in my mind.

I sensed that, Lakshmana, and I am unable to see you like this. For whatever little solace it is worth offering you, I am going to tell you a celestial secret which you are not supposed to tell anyone. Not even to Ram.

When your father visited the ashram of our kula guru, sage Vasishta, sage Durvasa had come to our kula guru's ashram. Durvasa being a sage who knows all the three times i.e. the past janmas of all living beings, present and the future, your father, emperor Dasarata inquired about the prospects of his four sons. Durvasa started narrating this event to Dasaratha, which will possibly explain why Rama is undergoing this suffering. As I happened to be there with your father as his trusted minister, I happened to listen it. I had kept this as a secret till now. But I think it's time to tell this to you alone now.

Durvasa said...

Once asuras took refuge in Sage Brihu's ashram protected by his wife. Devas got worried and requested Lord Vishnu to help them. When Lord Vishnu started fighting the asuras in Brihu's ashram, Brihu's wife tried to protect the asuras. Angered Vishnu cut Brihu's wife's head with his sudharsana chakra. Sage Brihu, unable to bear the loss of his wife, cursed Lord Vishnu that HE will be born as a human being and will suffer from separation from His wife. After cursing thus, sage Brihu came back to his calm senses and felt sorry for cursing Lord Vishnu. Vishnu consoled Brihu asking him not worry much and that he will respect the curse by taking a human avatar and experiencing the grief of separation from His wife. That Lord Vishnu has taken avatar as Ram, your son. His rule will be the best rule in the world. All His people will be happy. There won't be any crimes in His kingdom. There won't be any scarcity of food or wealth in His kingdom. But, he will suffer from the separation from His wife and His sons. This is something He has taken upon Himself.

PC: https://www.newindianexpress.com/magazine/2019/nov/24/ram-janmabhoomi-onus-of-dharma-on-lord-rama-2065936.html 

Saying this, Sumantra continued ... Ram has been a good son, a good brother, a good king for his people. All people are happy in his kingdom. But he is not going to be happy. He has to experience his karma palan. He has to miss his wife more than his wife misses him. That's his whole curse.

However Lakshmana, do not worry. His sons will grow up safely in Valmiki's ashram. When time is right, they will ascend the throne of Ayodya and continue the good rule of Ram. Ikshvaku clan won't be without successors.

Ram's suffering is predecided and is something that he has taken up on himself. You can't do much about it now. So, cheer up young lad. Just keep doing your duties.

JAI SHRI RAM!