What is the definition of provocation and what is the test for provocation?

provocation that causes a person to act, not out of rational thought but out of unconsidered reaction to the provocation." (People v. Beltran (2013) 56 Cal.4th 935, 942 (Beltran).) "[T]he provocation must be one that would cause an emotion so intense that an ordinary person would simply react, without reflection." (Id. at p. 949, original italics.) But the provocation is not required to be so great as to be "of a kind that would cause an ordinary person of average disposition to kill." (Id. at p. 935, original italics.)