知无不言

Explanation: Those who know do not say no. 　　Usage: Contraction type; as the predicate attribute; with compliment 　　Source: Su Xun Song "value of long and short term," all you know, laid to rest, hundreds of people of goodwill are not encrypted, hundreds of people without destroying the sparse. " 　　Examples: He was very straightforward, others to ask him, he always ~. Thesaurus:  speak (out) in meeting, Commit statement advise frankly