(Deut. 14:22:) “You shall surely tithe.” What is written above the matter (in Deut. 14:21)? “You shall eat no carcass [that is not properly slaughtered].” R. 'Azariah, R. Johanan ben Haggai, and R. Isaac bar Maryon said in the name or R. Jose bar Hanina, “One who eats his produce untithed is like one who eats carcasses and those torn (terefah). What is the reason? [It is first written (in Deut. 14:21),] ‘You shall eat no carcass.’
Then after that it is written (in vs. 22), ‘You shall surely tithe.’” R. Abin bar Rav Huna said in the name of R. Abba, “One who eats his produce without separating and [eats] tithes for the poor is liable for death.” R. Isaac said, “It is written in three places, ‘you shall not boil a kid in its mother's milk’: one for its own sake, one with reference to Torah, and one with reference to tithes. [Where the prohibition is given] for its own sake, what does it say (in Exod. 23:19)? ‘The choice first fruits of your land [you shall bring to the house of the Lord your God; you shall not boil a kid in its mother's milk.]’
What is written after that (in vs. 20), ‘Behold, I am sending an angel before you [to guard you on the way].’ With reference to Torah, it is written (in Exod. 34:26), ‘The choice first fruits of your land you shall bring to the house of the Lord your God; [you shall not boil a kid in its mother's milk.]’ What is written after it (in vs. 27)? ‘And the Lord said unto Moses, “Write down [these words].”’
With reference to tithes (in Deut. 14:22) it is written above (ibid.), ‘You shall eat no carcass […. You shall not boil (bshl) a kid (gedi) in its mother's milk (hlb).]’ Then after that is written (in Deut. 14:22), ‘You shall surely tithe.’ The Holy One, blessed be He, said, ‘Do not cause me to have the tender grains (gedayim) ripen prematurely (bshl) in the fat (hlb) of their mothers, while they are in the belly of their mothers (i.e., in their pods). Thus unless you take out a tithe properly, I will send out a certain wind from the east to blast them (i.e., the tender grains), just as you have said (in II Kings 19:26 = Is. 37:27), ‘and blasted before it is grown.’”