This discussion about the terminal illness nature of lay arahantship almost always fascinates me. That there could be such a downside to culminating the practice as a layperson (especially as a layperson with no Theravada temples within an hour's drive of me) is a bit scary...although, probably impending death isn't that big of a deal for an arahant.
One of the things that made my little ears perk up during S.N. Goenka's dhamma talks was a bit where he started talking about what happens when all the sankharas have been burned off with practice. That is, if sankaras are what give us rebirth in one moment and the next, what happens when we cease to generate them and burn all the old ones off? Well, he likens it to someone who is quite fat but stops eating. In theory the fat on the body could sustain the person, but once that fat is all gone, the person dies.
But as the Buddha points out, argument by analogy is one of those things that can turn out in two ways. I'd like to add on to the analogy—in a not quite physiologically correct way. So, once the fat of a person is all burned up, what is left to sustain them? Muscle and other tissue (those who have studied physiology know this is incorrect, you need proteins simultaneously with fat calories to sustain life, so muscle will waste away with fat during starvation).
I think in this way, kamma from the lives lived before arahantship become the sustaining factor. Even Mahamogallana had to suffer the consequences of his past awful kamma in his last days. A layperson has at least as much kamma to burn off as a monk: the kamma of having had sexual intercourse (children), the kamma of debt, the kamma of knowledge to be imparted, the kamma resulting in gifts to be accepted, any kamma from bad actions in the past. Until these kammas have all come to fruition, the arahant continues to live.
So, I tend to side with what Ajahn Chah said on the topic: It's not a literal dying. It's just dying to the worldly dhammas—Happiness&Suffering, Fame&Insignificance, Praise&Blame, Gain&Loss. It's hard to say exactly what an arahant—especially a lay arahant—would have to say in certain situations, but I've often felt there was truth in what the Perfect Monk says in the Jakata tale of The Curse of Mittavinda (here, rendered by Kurunegoda Piyatissa Maha Thera and Todd Anderson):
The wise monk understood that he (the monk that would eventually be reborn as Mittavinda) was jealous and resentful. He thought, "This monk does not understand my freedom from attachment to families, people, and comforts. I am free of any desire to remain here. I am free of any desire to leave here. It makes no difference. It is sad that this other one cannot understand nonattachment. I pity him the price he must pay for his ignorance."
...[The next day Mittavinda goes out for alms without his fellow monk]...
Meanwhile, back at the monastery, the perfect monk awoke. He cleaned himself and put on his robe. Then he calmly departed to collect alms food wherever he happened to find it.
I guess I was reading more into it when I first read it, but I figured the perfect monk left because although it did not matter to him whether he stayed or went, it mattered to Mittavinda. Likewise, I imagine a lay arahant thus: "What does it matter if I am a monastic or a layperson? I neither want to stay a layperson, nor not stay a layperson. I neither desire to be a monk nor not desire to be a monk. But if I were to abandon my children and spouse now, it would cause them to lose faith in the Buddha. I pity them this and so I will stay until it is the right time to leave." Hmm... now that I write it out, something about it seems not quite right, but perhaps that is because it's merely a piece of mental proliferation.
What I really meant is that an arahant layperson wouldn't have the worldly dhammas to motivate themselves; their motivation only takes into account what is best for others. I seem to recall a conversation between Buddha and an arahant. Buddha asked why the arahant continued in practice when the goal had been attained. The arahant answered, "To be a good example for those who are not yet arahants."
So there we go. I quite doubt that I am an arahant, but I sometimes ask myself, "What would an arahant do?" And test my planned course of action against the Nine Things an Arahant Cannot Do. Therefore, even though I long for the simplicity of wardrobe that the Triple Robe gives, I'm not going to abandon my spouse and children for what I regard as a simpler life. And it's not that I'm worried that the neighbors will whisper "Oh, what a bad parent, abandoning the children!" I just know that I can dhamma just as well here as in a monastery and that if I leave, my children could develop psychological issues that could eventually lead to suicide. I think that would count as "intentionally taking the life of a living being" and so I don't do it. One could say, "Ah, It might not happen!" Aye, when one pulls the trigger on a gun pointed at a person, one might not kill that person, but the probability is there. Better not to pull the trigger while the gun is pointing in that direction. Someday my children will not need me in this way, what difference does it make to me whether I join the order sooner or later? If for some reason I die of arahantship in the meantime, still, what does it matter?
Anyway, that's just my two cents. Sorry if I ranted; I have a lot of time on my hands today since I'm sick in bed.
Oh, an as for the part about not consuming stored up goods. I think it should be rephrased as "not enjoying stored-up goods." I think for many people there is a certain pleasure in having stored-up goods, like when one comes across a clearance sale of one's favorite candy that has been discontinued, one might get a bit greedy and buy the whole lot, just because it feels so good to know that you have this stash of that candy you like. For the lay arahant, it doesn't make a difference whether you have these things or not, if it seems like the time to give them away, you give them away. If the opportunity to give something away hasn't presented itself, you use the thing, but don't attach to it. What matters is you don't acquire new things purely out of desire. So, for example, a laywoman might accumilate many pairs of beautiful earrings before she becomes an arahant, but after she becomes and arahant, she neither desires to keep them nor desires to be rid of them. She does not crave new pairs, but does not reject those her husband gives to her. She wears them for skillful means or to suit the convention of being a wealthy laywoman, but if someone admires them, she decides if it is the right time and the right person to give them to. If it is, she takes them off and says, "Here, a gift." It not, she uses them as skillful means perhaps, but she certainly does not say, "I will not give these to you because they are MY earrings and I like them too much!"
So, I don't think it's the having that is contradictory to arahantship, but the attitude of attaching to what is stored up or enjoying having. But anyway, all of this is just mental proliferation. When one of you becomes a lay arahant, come back and let the rest of us know what it's really like.