The phrase "a declaration saying" is correct and usable in written English.
It can be used when referring to a formal statement or announcement that conveys specific information or intent.
Example: "The report included a declaration saying that all employees must adhere to the new safety protocols."
Alternatives: "a statement indicating" or "an announcement stating".
However, he has signed a declaration saying he will never own one - thus avoiding the fee.
"He sent me a declaration saying that he'd regretted writing the book.
General Musharraf issued a declaration saying that, unlike women, "we are not wearing bangles".
Fillon refused to answer their questions, and instead made a declaration saying his family's jobs were real and he had not broken the law.
We were told write a declaration saying "I, name and surname, pledge to vote for United Russia and these are my passport details..."...
Rather than try to convince resistant business owners to change their behaviour, they persuaded 3,500 ordinary citizens to sign a declaration saying they would buy goods from shops which did not pay the mafia.
The purpose of such a declaration, said Madison, was to mobilize public opinion.
The city Department of Recreation and Parks last month issued a report, called "A Negative Declaration," saying that the museum would not have a significant, adverse effect on the park environment.
"We would certainly need to inform our donors [about the law] and we'd need to get each of them who donated more than $250 to sign a statutory declaration saying they were an Australian resident [or] citizen," she said.
But in 2003, the editors of Science, Nature and The Proceedings of the National Academy of Sciences issued a joint declaration saying that occasions might indeed arise when a paper "should be modified, or not be published".
The leaders in Wales, Scotland and Northern Ireland issued a joint declaration, saying the coalition's cuts are "too fast and too deep" and may put the economic recovery at risk.
