An estimated 200,000 came from every alleyway and piazza near St. Peter's Square on Sunday afternoon to watch Pope Francis pray the Angelus for the first time since elected.

The Argentinean pontiff spoke through the window of his private study to a crowd that overflowed outside the square and into the streets. The multitude, larger than the night he was revealed, was colored by Argentinean, Italian, American and Brazilian flags; some stood staring at the multiple television screens that echoed the words said by the Pope.

A purposely casual pope in style, who refuses to wear the traditional gold-plated cross and forgoes the red papal cape or mozetta, spoke of forgiveness during his 15 minute speech.

In yet another first, Pope Francis delivered off-the-cuff remarks instead of reading from a written speech.

"Well, brothers and sisters, the face of God is that of a merciful father who always has patience," he said, casually welcoming the crowd, and referencing the episode of the adulterous woman who Jesus saves from a death sentence. "That is his mercy."

Pope Francis began his first Sunday as pope at the St. Anne Vatican parish where he was greeted by a choir at the entrance. At the private mass he spoke and read gospel on forgiveness and mercy similar to what he read in front of hundreds of thousands in the square.

He took the time to shake hands and speak to parishioners who wanted to meet him; one woman embraced him with a hug. 

One of the men accompanying the pope was seen pointing at his watch, and the pope signaled to him that he was going to stay a little longer, much to the chagrin of his security staff.

Back at the square, Pope Francis continued his speech and he went on to talk about a book by fellow Cardinal Kasper, calling him a "smart theologian."

"It did me much good that book, but don't think that I am advertising the books of my cardinals," he said to the laughs of thousands. "A little mercy makes the world less cold and more just."

Maria Eugenia Rettori, 30, lives in Rome but is from Argentina, and she was taken aback by Pope Francis' words as she watched from the square draped in an Argentine flag.

"I felt it was very sincere, very direct, and very humble," she said. "I think he's going to move the church closer to the poor, and to the people."

Following the prayer of the Angelus, the first Jesuit pope greeted all of those present in Italian. 

"I chose the name of the Patron of Italy, St. Francis of Assisi, and that reinforces my spiritual bond with this land, where as you know my family has its origins," Pope Francis said, who was born in Argentina to Italian immigrants.

The pope gave an inside story as to how his name was chosen in a meeting with the press on Saturday. He said that after he had won two-thirds vote, still inside the Sistine Chapel, Cardinal Claudio Hummes of Brazil told him "do not forget about the poor." At that point, he said, St. Francis of Assisi, revered as someone who helped the poor, came to his mind. 

He added some cardinals had joked that he should have been chosen Adrian VII, because Adrian the VI was seen as a great reformer, or Clement, as revenge for Pope Clement XIV's banishment of the Jesuits from the church.

Pope Francis showed the same common behavior when he received his first audience as pope on Saturday — the media. During his talk with the media he hugged chosen journalists and Vatican press personnel as they embraced him, an unheard of act for a pope. He also stood and received them, instead of staying seated on his chair.  

The pontiff is scheduled to meet with the President of Argentina, Cristina Kirchner, on Monday. The next day he will be inaugurated in a morning mass and celebration at St. Peter's square.

On Saturday he will fly from the Vatican heliport to have lunch with Pope Emeritus Benedict XVI at Castel Gandolfo, and on Sunday he will celebrate Palm Sunday in St. Peter's square at noon.

Pope Francis blessed the crowd on Sunday and before retreating back to his study said, "Do not forget this: the Lord never wearies of forgiving!"

Follow us on twitter.com/foxnewslatino
Like us at facebook.com/foxnewslatino

Bryan Llenas currently serves as a New York-based correspondent for Fox News Channel (FNC) and a reporter for Fox News Latino (FNL). Click here for more information on Bryan Llenas. Follow him on Twitter @BryanLlenas.

Follow us on twitter.com/foxnewslatino
Like us at facebook.com/foxnewslatino