Why seem to sell and be mafkir chametz?

Question

My understanding is that we do both of the following:

• We (appoint a rabbi as an agent to) sell our chametz to a gentile. This sale takes place the morning of the day before Pesach, before the prohibition of owning chametz kicks in.
• We renounce ownership in our chametz, declaring it ownerless. This also takes place the morning of the day before Pesach, before the prohibition of owning chametz kicks in.

Is seems, then, that whichever of these takes effect first renders us free of ownership of chametz, and whichever we do second therefore has no effect (unless one's acquired chametz meanwhile, an unlikely scenario). So why do the latter act (if, I mean, it has no effect anyway)?

Answer 1

Shulchan Aruch O.C. 448:5 rules that chometz which is found in your home after Pesach, even if you nullified it, is forbidden. The Tur there (cited by Magen Avraham and Taz) explains that we are worried that a person will say he nullified it even if he didn't. This isn't a problem for those crumbs that you don't want anyways. But for that box of cheerios you were planning on enjoying, it's a problem.

There is another reason that could be used to explain why it would be forbidden to use your chometz after you nullified it. If you nullify your chometz and declare that you consider it to be like dirt, and then start munching on it 9 days later, it would be a little bit of a contradiction to your nullification of it. (I can't remember where I saw this idea explicitly, but it is similar to the idea (Taz O.C. 442:8) that if you eat chometz which is degraded enough to not require getting rid of it, אחשביה, you have given it importance and reinstated its negated status.)

If you sell your chometz, you don't have these issues.

Selling your chometz would certainly not be prevented by having done bittul according to many Rishonim. While Tosefos (Pesachim 4b s.v. mid'oraisa) seems to hold that bittul accomplishes hefker, the implication of Rashi (ibid, s.v. b'bittul b'alma) and the explicit claim of the Ramban (Novelae to Pesachim 4b) is that bittul does not effect hefker and you still own your chometz. As the Ramban explains it, with bittul you are declaring acquiescense to the Torah's prohibition of chometz and submitting to the Torah's removal of chometz from your ownership. This happens after your sale takes effect. According to this view, you can "nullify" your chometz and still have ownership until the Torah removes it from your ownership at the 6th (or, Rabbinically, 5th) hour.

You would still want to do bittul, either to fulfill the mitzvah of tashbisu according to those who hold it is a fulfillment of the mitzvah (Ramban novelae to Pesachim, among others), or just to fulfill the Rabbinical enactment.

Answer 2

Shulchan Aruch HaRav (OC 431:4) writes that the Chachamim don't allow you to retain Chametz on your property during Pesach for two reasons: 1) You may not mean it when you say it is hefker and 2) you may forget and go eat it.

So if you are going to keep Chametz in your closet over Pesach, hefker won't be enough, it has to be sold. Selling Chametz is a much more recent practice.

Even if you have no Chametz (as was standard say 1,000 or more years ago) as the Chachamim didn't let you keep Chametz, hefker or not, they still required you to do the Bittul Chametz (Pesachim 6b). Shulchan Aruch HaRav (OC 434:6) explains that this is in case you missed a piece that isn't nullfied automatically and you happen to find it on Pesach - if you don't destroy it right away, you would be in violation of the Torah prohibition of owning Chametz.

In any event the point is that Bitul Chametz was a specific institution that the Chachamim made even though it is expected that you own no Chametz. So the subsequent practice of selling chametz (even if such a sale was actually to include the edible piece of Chametz that fell into a far corner - I don't think all sales are so thorough) doesn't remove the practice established by the Chachaimim to do Bittul Chametz.

Answer 3

The formulation for bitul chametz is is

כל חמירא וחמיעא דאיכא ברשותי, דחזיתיה ודלא חזיתיה, דבערתיה ודלא בערתיה, לבטיל ולהוי הפקר כעפרא דארעא"

Significant amounts of chametz cannot be nullified since it wouldn't realistically be possible to see it as "dust."

Answer 4

He might not mean the bittul sincerely - therefore, the bittul is not enough.

Selling chametz is something that is controversial. People sell chametz so that they will be able to eat it after Pesach. Also, many don't sell chametz gamur.