In keeping with presidential tradition, President Obama slipped a letter into the desk in the Oval Office for President-elect Donald Trump -- on Thursday the letter that George W. Bush wrote to him was released by Bush, as well as the letter that Bill Clinton wrote to Mr. Bush, each on the last day of his presidency. In the letters, Bush congratulated Mr. Obama but warned, “There will be trying moments. The critics will rage. Your ‘friends’ will disappoint you,” and Clinton told Bush, “The burdens you now shoulder are great, but often exaggerated. The sheer joy of doing what you believe is right is inexpressable.”

Eight years ago, George W. Bush wrote this to Mr. Obama:

“Dear Barack,

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Congratulations on becoming our president. You have just begun a fantastic chapter in your life.

“Very few have had the honor of knowing the responsibility you now feel. Very few know the excitement of the moment and the challenges you will face.

There will be trying moments. The critics will rage. Your ‘friends’ will disappoint you. But, you will have an Almighty God comfort you, a family who loves you, and a country that is pulling for you, including me. No matter what comes, you will be inspired by the character and compassion of the people you will lead.”

U.S. President Barack Obama walks with a letter before he departs the Oval Office for the final time as sitting president, at the White House in Washington, U.S. January 20, 2017. REUTERS/Jonathan Ernst

And before him. Bill Clinton wrote this:

Dear George,

Today, you embark on the greatest venture, with the greatest honor, that can come to an American citizen.

Like me, you are especially fortunate to lead our coutnry in a time of profound and largely positive change, when old questions, not just about the role of government, but about the very nature of our nation, must be answered anew.

You lead a proud, decent, good people. And from this day you are president of all of us. I salute you and wish you success and much happiness.

The burdens you now shoulder are great, but often exaggerated. The sheer joy of doing what you believe is right is inexpressable.

My prayers are with you and your family.”

The contents of Mr. Obama’s letter have not yet been disclosed, although he could be seen through the Oval Office window placing the note in the desk.

Here are the letters:

George W. Bush to Barack Obama, Jan. 20, 2009

Bill Clinton to George W. Bush, Jan. 20, 2001