Mischna zu Bamidbar 21:37

On that day they said: what is the law applying to Ammon and Moab in the seventh year? Rabbi Tarfon decreed tithe for the poor. And Rabbi Elazar ben Azariah decreed second tithe. Rabbi Ishmael said: Elazar ben Azariah, you must produce your proof because you are expressing the stricter view and whoever expresses a stricter view has the burden to produce the proof. Rabbi Elazar ben Azariah said to him: Ishmael, my brother, I have not deviated from the sequence of years, Tarfon, my brother, has deviated from it and the burden is upon him to produce the proof. Rabbi Tarfon answered: Egypt is outside the land of Israel, Ammon and Moab are outside the land of Israel: just as Egypt must give tithe for the poor in the seventh year, so must Ammon and Moab give tithe for the poor in the seventh year. Rabbi Elazar ben Azariah answered: Babylon is outside the land of Israel, Ammon and Moab are outside the land of Israel: just as Babylon must give second tithe in the seventh year, so must Ammon and Moab give second tithe in the seventh year. Rabbi Tarfon said: on Egypt which is near, they imposed tithe for the poor so that the poor of Israel might be supported by it during the seventh year; so on Ammon and Moab which are near, we should impose tithe for the poor so that the poor of Israel may be supported by it during the seventh year. Rabbi Elazar ben Azariah said to him: Behold, you are like one who would benefit them with gain, yet you are really as one who causes them to perish. Would you rob the heavens so that dew or rain should not descend? As it is said, "Will a man rob God? Yet you rob me. But you: How have we robbed You? In tithes and heave-offerings" (Malakhi 3:8). Rabbi Joshua said: Behold, I shall be as one who replies on behalf of Tarfon, my brother, but not in accordance with the substance of his arguments. The law regarding Egypt is a new act and the law regarding Babylon is an old act, and the law which is being argued before us is a new act. A new act should be argued from [another] new act, but a new act should not be argued from an old act. The law regarding Egypt is the act of the elders and the law regarding Babylon is the act of the prophets, and the law which is being argued before us is the act of the elders. Let one act of the elders be argued from [another] act of the elders, but let not an act of the elders be argued from an act of the prophets. The votes were counted and they decided that Ammon and Moab should give tithe for the poor in the seventh year. And when Rabbi Yose ben Durmaskit visited Rabbi Eliezer in Lod he said to him: what new thing did you have in the house of study today? He said to him: their votes were counted and they decided that Ammon and Moab must give tithe for the poor in the seventh year. Rabbi Eliezer wept and said: "The counsel of the Lord is with them that fear him: and his covenant, to make them know it" (Psalms 25:14). Go and tell them: Don't worry about your voting. I received a tradition from Rabbi Yohanan ben Zakkai who heard it from his teacher, and his teacher from his teacher, and so back to a halachah given to Moses from Sinai, that Ammon and Moab must give tithe for the poor in the seventh year.

Rabbi Joshua ben Levi said: every day a bat kol (a heavenly voice) goes forth from Mount Horeb and makes proclamation and says: “Woe unto humankind for their contempt towards the Torah”, for whoever does not occupy himself with the study of Torah is called, nazuf (the rebuked. As it is said, “Like a gold ring in the snout of a pig is a beautiful woman bereft of sense” (Proverbs 11:22). And it says, “And the tablets were the work of God, and the writing was the writing of God, graven upon the tablets” (Exodus 32:16). Read not haruth [‘graven’] but heruth [ ‘freedom’]. For there is no free man but one that occupies himself with the study of the Torah. And whoever regularly occupies himself with the study of the Torah he is surely exalted, as it is said, “And from Mattanah to Nahaliel; and Nahaliel to Bamoth” (Numbers 21:19).

Some materials raise the mikveh up [to the required quantity] and do not make it invalid. Some make it invalid and do not raise it up [to the required quantity]; And some neither raise it up [to the required quantity] nor make it invalid. These raise it up to the required quantity and do not make the mikveh invalid. Snow, hail, frosted dew, ice, salt, and thin mud. Rabbi Akiva said: Rabbi Ishmael once argued against me saying; snow does not raise up the mikveh [to its required quantity]. But the men of Madeba testified in his name that he had once told them: go and bring snow and with it prepare a mikveh from the outset. Rabbi Yohanan ben Nuri says: hailstones are like drawn water. How do they raise it up [to the required quantity] and not render it invalid? If the mikveh contained forty seahs less one, and a se'ah of them fell in and made up [the required quantity], they thus make up [the required quantity] but do not render it invalid.