A deal in spiritual terms is a negotiation between two aspects of self: the ‘higher’ part, which knows what is right from a cosmic perspective, and the lower part, which is more concerned with everyday matters.
Psychological / emotional perspective: When there is some difficulty in integrating all parts of the personality we will often dream of a deal in order to clarify what action we need to take.
Material aspects: As so much of everyday life is taken up with deals and negotiations we will often mirror such situations in dreams.
To be dealing cards may suggest taking a gamble or a calculated risk.
Gives gender - specific: In a woman’s dream a deal is likely to highlight aspects of her masculine, more driven side but in a man’s dream it may be the more intuitive skills which come to prominence. Both, of course, are skills required in efficient negotiation in the ordinary world.