Portia finds herself in a most unfortunate situation because her father has willed that she may only marry a man who chooses the correct casket of three: gold, silver and lead. He has placed, before his death, messages in each of the three chests but only one congratulates the suitor on his success whilst the other two mocks him for making the wrong choice.
Portia is, therefore, the winning prize in a lottery arranged by her deceased father. She may not assist any of the suitors or provide them any clues as to which is the correct choice for she would then forfeit her entire inheritance. Since her father had been an extremely wealthy man and she was a beautiful young lass, many suitors came to her island home, Belmont, to chance their luck. The suitors, themselves, were wealthy young men with titles and status. Such a person was the prince of Morocco.
When she hears of the prince's imminent arrival, Portia confides to Nerissa, her waiting-lady:
be glad of his approach: if he have the condition
of a saint and the complexion of a devil, I had
rather he should shrive me than wive me.
Portia here clearly expresses her disdain. She is not happy that the prince would be coming to chance his luck but has to pretend to be, for appearance' sake; that is why she uses the word 'should.' Her remark as to the prince's complexion has numerous interpretations, but she would not be pleased if he appeared unpleasant. She would then rather have him forgive her of her sins or exclude her from his choice for a wife than to actually marry her.
When the prince eventually makes his entry in Act 2, scene 1, he asks Portia not to hate him for his looks. In her reply, Portia tells him:
In terms of choice I am not solely led
By nice direction of a maiden's eyes;
Besides, the lottery of my destiny
Bars me the right of voluntary choosing:
But if my father had not scanted me
And hedged me by his wit, to yield myself
His wife who wins me by that means I told you,
Yourself, renowned prince, then stood as fair
As any comer I have look'd on yet
For my affection.
She means that she is not only guided by good looks and furthermore, she does not have any choice in the matter because of her father's will and she is therefore compelled to give herself to him if he should choose correctly. She assures the prince that if these were not the conditions, he would have stood as much a chance of winning her hand as any man. She would have no particular prejudice against him.
In saying this, Portia shows her breeding and stature. She is courteous to the prince and does not wish to offend him. As such, she speaks like a gentlewoman should and, instead of being harsh and dismissive or even rude, she makes him feel welcome and just as much the equal of any other man who may want to win her affection. The prince is impressed by her courtesy and generously thanks her.
Later, in scene 7, when the prince is at the point of making his choice, Portia refers to the prince as 'noble', again displaying her generosity and genteel nature. She assures the prince when he asks how he would know if he had chosen the correct chest, by saying:
The one of them contains my picture, prince:
If you choose that, then I am yours withal.
She would be the prince's completely if he should choose right.
Once the prince has made his choice, which turns out to be the wrong one, he leaves immediately. Portia breathes an obvious sigh of relief and says:
A gentle riddance. Draw the curtains, go.
Let all of his complexion choose me so.
She is happy that she is so easily rid of the prince.