take an oath
make an oath
swear an oath

You took an oath to care for her, just like the rest of us.

The king would have to take an oath to the state.

I held up my hand as if taking an oath.

As a result, she did not take her oath of office.

Being considered too young, he had to wait another year to take his oath of law.

He did, and I took the oath all over again.

In just 45 months, someone will be taking the oath of national office.

His hand went up to take the oath with the others.

The court said he had already taken the oath of office.

She took the oath of office on May 21, 2010.