Prime Cabinet Secretary Musalia Mudavadi did not lift the Bible during his swearing-in on Thursday, October 27 at State House, Nairobi.
Mudavadi, instead, lifted his right hand while taking the oath of office presided over by President William Ruto.
Out of the 25 State officers who took the oath of office, including the Head of Public Service Felix Koskei, only Mudavadi did not use a religious book during swearing-in.
Defence Cabinet Secretary Aden Duale, a Muslim, used the Quran during his swearing-in.
The happenings televised live had a section of viewers questioning why Mudavadi failed to lift the Bible during oath-taking.
The Standard understands that Musalia Mudavadi's faith does not allow him to use a religious book during oath.
Mudavadi belongs to the Quaker faith, whose doctrines do not allow him to use a religious book during oath.
Speaking to The Standard, Kenya's Friends' Church Presiding Clerk Henry Mukhwana said their faith only recognises an individual's personal efforts to commit to the pledge made during oath, and not necessarily using a religious book to show that commitment.
In 2016, when Mudavadi expressed interest in the presidency ahead of the August 8, 2017 General Election, he told The Standard that he was a member of the Quaker faith, making him the best candidate for presidency.
"We need a religious nation. And for us to get this religious nation, we need a religious president. As you know, Quakers are very religious," he said.
According to the BBC, Quakers are members of a group with Christian roots that began in England in the 1650s.
Although outsiders usually regard the movement as Christians, not all Quakers see themselves as Christians.
Some regard themselves as members of a universal religion that has many Christian elements.
The formal title of the movement is the Society of Friends or the Religious Society of Friends.
One story says that the founder, George Fox an Englishman, once told a magistrate to tremble (quake) at the name of God and the name "Quakers" stuck.
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Other people suggest that the name was derived from the physical shaking that sometimes went with Quaker religious experiences.
The name "Friends" comes from Jesus' remark: "You are my friends if you do what I command you" (John 15:14).
Quakers are known by their chain of "Friends" schools and hospitals.
In Kenya, the first school founded by Quakers was Friends' School Kaimosi in Vihiga County, where Musalia Mudavadi comes from.
Kaimosi is actually the town inhabited heavily by Quakers in Kenya, with many members of the Maragoli sub-tribe belonging to the faith.
Globally, there are about 400,000 people who are members of the Quakers faith, according to Philadelphia-based Friends Center.
According to the BBC, Quakers believe that there is something of God in everybody and that each human being is of unique worth.
"This is why Quakers value all people equally, and oppose anything that may harm or threaten them," says the British outlet.
Quakers seek religious truth in inner experience, and place great reliance on conscience as the basis of morality.
They believe that everyone can have a direct, personal relationship with God without involving a priest or minister.
They also believe that rituals are an unnecessary obstruction between the believer and God.
"They further believe that redemption and the kingdom of heaven are to be experienced now, in this world," says the BBC.
Quakers do not regard any book as being the actual "word of God".
Most Quakers regard the Bible as a very great inspirational book but they don't see it as the only one. As a result, they read other books that can guide their lives.
Quakers do not celebrate Christian festivals such as Easter or Christmas.
Quaker communal worship consists of silent waiting, with participants contributing as the spirit moves them.
Quakers neither practice baptism nor celebrate the Eucharist. They don't regard some activities as more sacred than others, nor do they believe that any particular ritual is needed to get in touch with God.
At the same time, Quakers have no collective view on what happens after death.
"They tend to concentrate on making this world better rather than pondering what happens after leaving it," says the BBC.
Quaker meetings for worship take place in meeting houses, not churches. These are simple buildings or rooms.
A meeting begins when two or more worshipers come together to be in the presence of God. They usually sit facing each other in a square or a circle.
"This helps them to be aware that they are a group together for worship, and puts everybody in a place of equal status," says the BBC.
Quakers are forbidden from gambling. However, they are free to use alcohol or tobacco, but most of them choose not to, or consume them moderately.
Quakers are non-judgemental about sex, which they see as a gift of God.
They believe in the sanctity of marriage, but also recognise the value of non-marital relationships and singlehood.
During their weddings, there are no priests or ministers to lead a couple as they exchange vows.
Quakers don't have any clergy. They, instead, appoint elders.
Law doesn't demand religious book during oath
Away from Mudavadi's faith, the law doesn't require a State officer in Kenya to take oath using a religious book.
In February 2016, Supreme Court Judge Isaac Lenaola, who was at the Constitutional and Human Rights Court, ruled that Article 74 of the Kenyan Constitution does not require one to use a religious book during oath-taking.
Lenaola further observed that Article 32 of the Constitution allows one to profess any lawful faith, and shouldn't be discriminated upon when assuming State office.
Even in established democracies like the United States, Bibles or Qurans aren't mandatory during oath-taking.
"The American law requires that senators and representatives take an oath or affirmation to support the Constitution, but it says nothing about using the Bible. The law further says no religious test shall ever be required as a qualification to any office," says FactCheck.org.
US presidents who did not use Bible during oath
In the US, placing a hand on a Bible while reciting the presidential oath was a tradition started by George Washington.
Two presidents, Theodore Roosevelt and John Quincy Adams, did not use a Bible at their swearing-in ceremonies.
CNN reports that Adams, the son of President John Adams, was a religious man, but he chose to be sworn in with his hand on a book of United States laws.
"He wanted to demonstrate that he recognised a barrier between church and state and that his loyalty was to the United State of America's laws above all else," said CNN in a January 20, 2013 article.
Theodore Roosevelt was sworn in is as the 26th President of the United States upon the assassination of William McKinley.
McKinley was shot by Leon F. Czolgosz in Buffalo, New York on September 6, 1901, but died on September 14, 1901.
Reports state that to avoid a power vacuum, there was no time to plan a swearing-in ceremony for Roosevelt.
As a result, Roosevelt, who had visited a friend, Ansley Wilcox, in Buffalo, New York had to take the oath of office urgently, on the same day McKinley died (September 14, 1901). There was no Bible in Wilcox's house, leading to Roosevelt taking the oath office without a Bible.
The oath was administered to Theodore Roosevelt by John R. Hazel, the US District Judge of the Western District of New York.