''Where's the Thane of Cawdor?'' Where do you think Macbeth is as his wife greets the king at the gate?
Hmmmm, sharpening his knife while putting on a grand facade, ... perhaps mixed with a little bit of I-really-want-to-avoid-this-as-long-as-I-can type of amalgamation, I would think? Ha!
I'll admit I had to laugh at the image of Macbeth being wrapped up in "household kitchen duties." I can't imagine Macbeth slaughtering a stuck pig, ... or gathering eggs in baskets like a maiden. I'm not sure his ambition would allow him to stoop that low. Remember, it is Lady Macbeth who is encouraging this. Here she is, ... out in front yet again. Macbeth always seems to be waiting in the wings, doesn't he? Very telling.
My only issue about the correct protocol spoken about above is that, if this were absolutely so, ... then why does Duncan ask about it? If it were truly protocol, then Duncan would know exactly where Macbeth is. Most likely, it was probably protocol for the head of the household to greet such an admirable guest as the king. How interesting that Lady Macbeth here acts as the head of household and host.
Regardless of all this conjecture, this is actually a very fascinating question that I enjoyed contemplating!
I think that Macbeth required much more contemplation to compose himself to greet Duncan than Lady Macbeth does. She is much more skilled at being deceptive and is more resolute in the plan to kill Duncan. Macbeth has a great loyalty to his monarch and, as he will tell us later, he has little reason to exert such a cruel end on a king who has supported and honoured him.
I agree that the appearance of Lady Macbeth first, then her husband would also add to the pomp of accepting a royal visitor. However, I think Shakespeare is indicating to us that at this point Lady Macbeth is stronger in terms of her ability to flatter and deceive the king they will kill than Macbeth is.
I am in agreement with the above posters. The Macbeths had to split duties...he rode ahead to warn everyone of the huge posse coming with the King. There were not enough servants, and probably there was not enough food on hand. As his lovely wife welcomed Duncan to their castle, Lord Macbeth was most likely busy with household kitchen duties, or perhaps, slaughtering something to prepare for the meals.
Clearly, Macbeth and Lady Macbeth did not have enough servants. When Banquo is commending Macbeth by sharing King Duncan's gratitude for a wonderful evening, Macbeth admits that his wishes made the difference in being unprepared:
Our wishes became the servants to what we lacked,
Which has worked out very well.
With this being said, Macbeth was no doubt busy in trying to get the evening meal prepared. After all, King Duncan brought a host of people. Macbeth admits that he was unprepared. Most likely, he was just as busy as the servants in preparation for King Duncan.
Macbeth has done enough wavering (about whether or not to murder the king) before Duncan arrives that it may be that Macbeth is screwing his courage to the sticking point and putting on his "game face" for the events he and Lady Macbeth have planned for the night.
Being a king is all about impressing and being impressed. It's all pomp and circumstance. There is careful protocol to be followed. Macbeth is not going to answer his own doorbell, so to speak. I agree with the others that there is also protocol to be followed for receiving lofty visitors.
I think #3 makes an excellent point. The speech of Duncan allows us to infer that Macbeth was following a set protocol in terms of how to welcome one's king to one's castle. Using the wife to give the first welcome, and then having a second welcome provided by the man might have been the way things were done then.
Alternatively, a more interesting suggestion is to guess that Macbeth has gone to compose himself, having been told by Lady Macbeth to pull himself together as he is struggling with his internal conflict of whether to kill Duncan or not.
One suggestion of where Macbeth is when King Duncan arrives is that he is in his throne room or elsewhere preparing himself to give an imposing welcome to the King. There was a protocol--as there is now--for how royalty are to be greeted by their lieges. This is confirmed by Duncan's reaction and response. His reaction is perfectly at ease and comfortable with being greeted only by Lady Macbeth indicating that such a greeting was expected. His response, upon extending her his hand, is to genially require he be taken to Macbeth:
It's hard to know for sure where Macbeth is while Lady Macbeth greets Duncan upon his arrival at Inverness, in Shakespeare's Macbeth. We can draw some logical conclusions.
It is quite possible that Macbeth is making arrangements for the King's arrival. One might expect that this would fall to the woman of the house, preparing rooms and food, rather than to the master of the castle. However, Lady Macbeth speaks to this later.
Knowing Macbeth has his eye on the throne, we might surmise that he is already plotting how the murder will take place: in this case, it would be important to place the King where his guards would be housed nearby but where Macbeth would have easy access to Duncan while he sleeps. However, Lady Macbeth also mentions this part of the plan: she knows what she wants done.
When Macbeth arrives at the castle, following his letter containing news of the witches' predictions and his own "promotion" to the Thane of Cawdor, Lady Macbeth gives him advice, and he may be following it while she welcomes the King. She comments as Duncan approaches (with plans to leave the next day) that he will never wake to see the dawn. She then tells Macbeth that he is too easily read. His face is like "an open book" where his thoughts can be easily read, so he must be careful to keep his thoughts off of his face. She says:
...look like the innocent flower, / But be the serpent under't. (I.v.64-65)
Lady Macbeth goes on to say that the King must be provided for. So Macbeth may be doing just that because she then tells her husband to leave the details to her:
...you shall put / This night's great business into my dispatch...
This indicates how hard-hearted she really is—that she can smile in the King's face, while planning to kill him that night.