Listen here. It's pretty funny the way they tell it.
An "abundance of caution" prompted the chief justice John Roberts to re-administer the oath:
CNN: The second oath took place at 7:35 p.m. Wednesday in the White House's Map Room, according to a pool reporter who witnessed it.
"Are you ready to take the oath?" Roberts asked.
"I am, and we're going to do it very slowly," Obama replied.
On Tuesday, Roberts, apparently working without a copy of the oath handy, started out by reciting a six-word phrase, but Obama broke in halfway through and repeated the first three.
That seemed to throw the chief justice off stride, and he proceeded to mix up the order of the words in the next phrase.
The Constitution sets out the language that should be used in the oath: "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."
Roberts moved the word "faithfully" back nine spots, and used "to" instead of "of." That threw the president off base, and he smiled and paused to collect his thoughts, then decided to follow Roberts' lead.
But the chief justice at the same time attempted to correct himself.
Here's how Tuesday's oath went:
Roberts: ... that I will execute the office of president to the United States faithfully ...
Obama: ... that I will execute ...
Roberts: ... the off -- faithfully the pres -- the office of president of the United States ...
Obama (at the same time): ... the office of president of the United States faithfully ...
The two got the rest correct, including the nonobligatory "So help you God?" "So help me God."
Roberts has made no comment on becoming tongue-tied Tuesday.