October 31 is also the death anniversary of Indira Gandhi. During his Mann ki Baat radio address, Modi was referring to the 1984 anti-Sikh riots that broke out soon after the former Prime Minister was assassinated by her bodyguards.
Modi's mention of the Sikh riots followed a call from a Punjab resident who identified himself as Jashdeep.
The caller had brought up the irony of Patel's birth anniversary coinciding with Indira's assassination and the violence it triggered, seeking to know from the Prime Minister how such incidents could be stopped.
After the call, the Prime Minister took the issue forward. "My dear countrymen, this pain is not just of one person," he said in his pre-recorded monthly radio address.
Modi held up Vallabhbhai Patel - popularly known as Sardar (leader) - as the man who had achieved the Herculean task of unifying the country. "Sardar sahab lived and struggled for unity. It is painful that on the birth anniversary of the same Sardar, thousands of sardars, thousands of sardarfamilies, were murdered after the killing of Indira Gandhi," the Prime Minister said.
He said this chapter of history, the "atrocity against sardars" on the "birthday of the Sardar", would "continue to give pain to us".
The move to juxtapose the two - Patel's birth anniversary and the violence againstsardars, as Sikh men are commonly referred to - came ahead of next year's Assembly elections in Punjab, where the BJP and ally Akali Dal are said to be on a sticky wicket.
Modi made no reference to the contributions of Indira, but showered praise on Patel, independent India's first home minister who is credited with playing a key role in getting over 500 princely states to integrate with the rest of the country.
He said after Chanakya, widely recognised for his role in building the Mauryan empire, Patel had helped unite the country under one flag.
Although Patel was a Congress leader, the BJP has embraced the freedom fighter from Gujarat as one of its own. The party alleges that the Congress suppressed Patel's contribution to highlight that of Jawaharlal Nehru.
The Modi government, which came to power in 2014, has declared October 31 as "national unity day".
The government celebrates Patel's birth anniversary with fanfare; there is hardly any mention of Indira's death anniversary. When the Congress was in power, the party had also been accused of lionising only those associated with the Nehru-Gandhi family and ignoring others.
Today, the government put out advertisements in newspapers to announce the dedication of a digital exhibition titledUniting India: Sardar Patel by the Prime Minister tomorrow.
Modi also credited Patel with envisioning the cooperative milk federation and said Amul owed its success to the leader.
The Congress, desperate to uphold Indira's legacy, also brought out newspaper advertisements that said: "Remembering Indira Gandhi on the 32nd anniversary of her martyrdom."
The Congress advertisement quoted Indira to underline the unity of caste, religion and community.
"The citizenship of India is a shared citizenship. Danger to even one citizen, to whatever community, caste, religion, or linguistic group he may belong, is a danger to all of us, and what is worse, it demeans us all," the quote, attributed to Indira alongside her picture in the Congress advertisement, said.
Shakti Sthal, the memorial to Indira beside the Yamuna in Delhi, has been locked up this year by the government following a suspected bird-flu scare.
The memorial was locked after four bird carcasses were found on its premises. Samples have been sent for tests and the results are awaited.
While ruing the unfortunate coincidence of Patel's birth anniversary and Indira's death anniversary, Modi expressed his commitment to maintaining India's unity by trying to project himself as a follower of the Iron Man.
"Unity in diversity is the strength of the country," he said, adding that despite many languages, many castes, different attires and different food habits, unity was the country's strength and special feature.
"It is the responsibility of every generation, every government to look for opportunities of unity in every corner of the country and save ourselves from sectarian ideas and sectarian tendencies," Modi said.
The reference to Patel and Indira came against the backdrop of Modi celebrating the valour of the armed forces on Diwali.
The Prime Minister saluted the bravery of the soldiers, lauded their sacrifice and dedicated the festival to the armed forces.
The government has been playing up the issue of nationalism since the army's September 29 surgical strikes across the Line of Control. The Prime Minister, however, did not make any specific reference to the recent decapitation of a soldier by "terrorists" who had sneaked across the LoC.
"In the wake of the recent events, our soldiers have been sacrificing everything for the safety and security of the country. Their dedication and labour has overwhelmed me completely. Let us dedicate this Diwali to our armed forces," Modi said.
The Prime Minister today spent Diwali with Indo-Tibetan Border Police troopers near the China border in Himachal Pradesh.