For Marriage
It is very bad. Do not do it under any circumstances, or you will deeply regret it.
For Business / Deal
It is very bad; you will be deceived and suffer a massive loss.
۞ قُلْ كُونُوا حِجَارَةً أَوْ حَدِيدًا
Qul koonoo hijaratan aw hadeedan
Say: "(Nay!) be ye stones or iron,