"Baba is here. I have heard your cries and suffering and after going quiet for a while, I have come here to hear you and I am ready to help," said Raila to his cheering supporters.
Attacking the Kenya Kwanza's government for what he said was a 'slow takeoff' in fulfilling its pledges, the Azimio leader swore to keep the new government in check and ensure that services are delivered to the people.
Raila criticised some of the strategies and decisions the new government has put in place, including the alleged resale of 'free fertilisers' from Russia and the "arbitrary introduction of genetically modified organisms in the country without adequate research".
"After 100 days, we will start asking them questions. The other day they were given free fertilisers from Russia and now they are selling the same fertiliser to farmers for Sh3,500.
"During the campaigns they promised the price of maize flour and fuel would go down. Has it gone down? I told you all this was meaningless talk. They were telling lies," said Raila.
Raila criticised the government for saying the country was broke "yet the president has taken a number of trips outside the country in his one month in office.
"They claimed the government is bankrupt but the same month, they went to bury the queen and later went to America. Those trips cost the taxpayers Sh200 million," said Raila.
The former prime minister also weighed in on President Ruto's decision to privatise five to 10 State corporations through the Nairobi Stock Exchange (NSE) and allow Kenyans the opportunity to buy into the companies.
He argued that it was "impossible" for hustlers to participate in such an endeavor when they have little or no income.
"You can only invest in the stock exchange if you have disposable income. But bodaboda riders and mama mbogas don't have that kind of money. How can they invest in the stock exchange?" he posed.
The veteran politician who has reinvented himself over the years after several failed attempts at the presidency looked to be out to reclaim his position as the force behind the opposition with yesterday's rally being the second this week after he addressed members of Bunge La Mwananchi at Jevanjee Gardens in Nairobi on Tuesday.
Under the cloud of rising cost of living, a struggling business environment and low income among majority of Kenyans, Raila's presence in Mathare was a cause for jubilation for many of his supporters still smarting after his loss in the August polls.