The phrase "get assurance from" is correct and can be used in written English.
It is typically used to mean to ask or attempt to receive reassurance from someone. For example: I'm nervous about my job interview, so I'm going to get assurance from my friend that I'm ready for it.
Pettitte called Cashman on Wednesday morning to "get assurance from me that he's not somehow messing our plans up," Cashman said.
"Despite numerous conversations, I still have not been able to get assurance from Chancellor Levy that there won't be any more unqualified teachers in these schools in September," Mr. Mills said in an interview yesterday.
If consumers don't get assurance from you, they won't stick around for it; they'll take their business elsewhere.
Get assurance from your breeder or rescue agency that the new dog is healthy.
And some election boards were struggling to find power or get assurances from the utilities that power would be restored in time.
It is separate from the court's initial bar on deportation, which required the Government to first get assurances from Jordan that evidence gained through torture would not be used against Qatada if he is sent back.
Broadly, the sticking points center on Florida and Alabama trying to get assurances from Georgia that it will not siphon off too much water from the headwaters, thereby leaving the two downstream states wanting.
"The United Nations made every effort to get assurances from all parties, only for the parties to then fail to agree on each other's conditions about how evacuations should proceed.
America shows signs of inserting a "buy American" clause into its economic recovery package but Brown will want to get assurances from Obama before the G20 that he too will sign up to a pledge against protectionism in the eventual communique.
The government was also working hard to try to get assurances from Jordan that would satisfy the European Court that Abu Qatada could be deported, she said.
The U.K. government, the Guardian newspaper and France's Havas (the world's sixth-largest advertising and marketing company) pulled ads from Google and YouTube on Friday after failing to get assurances from Google that the ads wouldn't appear next to offensive material.
