Shafaq News/ The Shiite representative in the historical city of Ur presented the Pope Francis a letter written by Imam Ali 1400 years ago.

The letter presented to the Pontiff stipulated, "People are of two types: Either your brother in faith or your equal in humanity."

Pope Francis held a historic meeting with a senior Shiite cleric in Iraq Saturday and appealed for greater interfaith unity visiting the birthplace of Abraham, as part of his whirlwind tour of the Middle Eastern country.

Francis, 84, met with Grand Ayatollah Ali al-Sistani, 90, at his home in the holy city of Najaf in central Iraq, where the two elderly men of faith provided a highly symbolic moment of tolerance, for a country scarred by sectarianism and violence.

Iraq's Prime Minister Mustafa al-Kadhimi called the meeting "historic" on Twitter and declared March 6 an annual 'National Day of Tolerance and Coexistence' in Iraq.

After the meeting, Francis travelled to the desert plain of Ur in southern Iraq, revered as the birthplace of Abraham — the patriarch of monotheism and a unifying prophet in Islam, Christianity and Judaism.