[If] someone makes his dough kav portions and they touched one another, they are exempt from challah until they bite [one another]. R' Eliezer says: Also [if] one removes [loaves of bread from the oven] and places [them] in a basket, the basket com-bines them to [render them obligated in] challah.

[If] one separates his challah [from] flour, it is not challah, and is [considered] stolen [as long as it remains] in the hands of the Kohen [to whom it was given]. The dough itself is obligated in challah; and the flour, if it consists of the [minimum] measure, is obligated in challah and is forbidden to non-Kohanim; [these are] the words of R' Yehoshua. They said to him: There was an incident [in which flour was designated as challah] and a sage who was a non-Kohen grabbed it. He said to them: He, too, ruined matters for himself, [though] he fixed them for others.

Five reva'im of flour are obligated in challah. [If] it, its sourdough, its fine bran, and its coarse bran [total] five reva'im —- [the dough] is obligated [in challah]. [If] the coarse bran was removed from [the flour] and then returned to it, [the dough] is exempt [from challah].

The measure of challah is one twenty-fourth [of the dough]. [For] one who makes a dough for himself, and [for] one who makes [a dough] for his son's feast, [the measure is] one twenty-fourth. [For] a baker who is making [bread] to sell at the market, and, likewise, [for] a woman who is making [bread] to sell at the market, [the measure is] one forty-eighth.  [If] her dough became tamei mistakenly or accidentally, [the measure is] one forty-eighth. [If] it became tamei intentionally, [the measure is] one twenty-fourth, so that the transgressor should not profit [from her transgression].