Mischna zu Schemot 12:55

If one has eaten of [these five] on Pesah an olive-size piece of matzah, he has fulfilled his obligation. [If he ate on Pesah] an olive-size of piece of hametz [made of these grains], he is liable for karet. If one of these [grains, having become leavened,] became mixed with any other species, one must remove it on Pesah. If one has vowed [to abstain] from [consuming] bread and tevuah (produce), he is prohibited from consuming these [five species] the words of Rabbi Meir. The sages say: if one has vowed [to abstain] from [consuming] dagan, is prohibited only from [consuming] these [species] only. They are subject to hallah and tithes.

Rabbi Halafta of Kefar Hanania said: when ten sit together and occupy themselves with Torah, the Shechinah abides among them, as it is said: “God stands in the congregation of God” (Psalm 82:1). How do we know that the same is true even of five? As it is said: “This band of His He has established on earth” (Amos 9:6). How do we know that the same is true even of three? As it is said: “In the midst of the judges He judges” (Psalm 82:1) How do we know that the same is true even of two? As it is said: “Then they that fear the Lord spoke one with another, and the Lord hearkened, and heard” (Malachi 3:16). How do we know that the same is true even of one? As it is said: “In every place where I cause my name to be mentioned I will come unto you and bless you” (Exodus 20:21).

Also he declared three decisions of a lenient character:One may sweep up [on a festival] between the couches, And put spices [on the coals] on a festival; And roast a kid whole on the night of Passover. But the sages forbid them.

The following cases are [examples] of the lenient rulings of Beth Shammai and of the rigorous rulings of Beth Hillel.An egg which is laid on a festival Beth Shammai says: it may be eaten, and Beth Hillel says: it may not be eaten. Beth Shammai says: yeast as much as an olive [in quantity], and leavened food as much as a date, and Beth Hillel says: as much as an olive [in quantity] in both cases.

Rabbi Yose says: there are six instances of lenient rulings by Beth Shammai and stringent rulings by Beth Hillel.A fowl may be put on a table [together] with cheese but may not be eaten [with it], according to the opinion of Beth Shammai. But Beth Hillel says: it may neither be put on [the table together with it] nor eaten [with it]. Olives may be given as terumah for oil and grapes for wine, according to the opinion of Beth Shammai. But Beth Hillel says: they may not be given. One who sows seed [within] four cubits of a vineyard: Beth Shammai says: he has caused one row [of vines] to be prohibited. But Beth Hillel says: he has caused two rows to be prohibited. Flour paste [flour that had been mixed with boiling water]: Beth Shammai exempts [from the law of hallah]; But Beth Hillel pronounces it liable. One may immerse oneself in a rain-torrent, according to the opinion of Beth Shammai; But Beth Hillel say: one may not immerse oneself [therein]. One who became a proselyte on the eve of Passover: Beth Shammai says: he may immerse himself and eat his Passover sacrifice in the evening. But Beth Hillel says: one who separates himself from uncircumcision is as one who separates himself from the grave.