Question not to be asked without reasonable grounds
151.  No such question as is referred to in section 150 ought to be asked unless the person asking it has reasonable grounds for thinking that the imputation which it conveys is well founded.
Illustrations

    (a)  An advocate is instructed by a solicitor that an important witness is a professional gambler. This is a reasonable ground for asking the witness whether he is a professional gambler.

    (b)  An advocate is informed by a person in court that an important witness is a professional gambler. The informant, on being questioned by the advocate, gives satisfactory reasons for his statement. This is a reasonable ground for asking the witness whether he is a professional gambler.

    (c)  A witness of whom nothing whatever is known, is asked at random whether he is a professional gambler. There are here no reasonable grounds for the question.

    (d)  A witness of whom nothing whatever is known being questioned as to his mode of life and means of living gives unsatisfactory answers. This may be a reasonable ground for asking him if he is a professional gambler.