The letter was shared by the former president on Twitter today.
At a time when bitterness in politics was on the rise, Modi's letter was an example of a mindset based on ideal public values and great traditions, he told a press conference here.
"This is also an ideal for the country's politics," Shah said, adding Modi's "intimate" letter and Mukherjee's affectionate reply spelt out the bond between the two leaders drawn from different political ideologies.
"I read the letter after it was shared on the social media. Modiji is emotional by nature. But, the way he praised Mukherjee in the letter, I believe that in the coming decades, the kind of respect and behaviour a prime minister should have towards the president, PM Modi has set an example in this regard," Shah said.
More From This Section
In the letter to Mukherjee, an emotional Modi had written, "Pranab Da, you have always been a father figure and a mentor to me".
Modi responded by saying, "Pranab Da, I will always cherish working with you."
Shah said Mukherjee was never associated with the BJP but when the BJP government was formed, neither the prime minister ever felt that Pranab 'Babu' belonged to a different ideology and nor did Mukherjee feel that this government was of some other party.
The BJP national president had arrived here yesterday on a three-day visit to Haryana. With an eye on the 2019 Lok Sabha polls, he is on a countrywide tour to strategise and find ways to strengthen the party at the grassroot level.