Shabbat 51A

לא משום כלאים, ולא משום שביעית, ולא משום מעשר, וניטלין בשבת! תיובתא.

due to diverse kinds, i.e., that he violated the prohibition of planting food crops in a vineyard, as he did not commit an act of planting; nor due to concern that he violated the prohibition against working the land during the Sabbatical Year; nor due to tithes, i.e., that it would be considered as if he picked it from the ground and would be obligated to tithe it; and they may be taken from the ground on Shabbat. Even if most of the turnip or radish is underground, it is permitted to pull it from the ground on Shabbat. One need not be concerned about causing the earth to move. Apparently, this contradicts the opinions of Rav Huna and Shmuel, who were concerned about causing earth to move on Shabbat. The Talmud concludes: Indeed, this is a conclusive refutation of the opinions of Rav Huna and Shmuel.

מתני׳ לא כסהו מבעוד יום ⁠— לא יכסנו משתחשך. כסהו ונתגלה, מותר לכסותו. ממלא את הקיתון ונותן לתחת הכר או תחת הכסת.

Mishnah: If one did not cover a pot of cooked food on Friday while it was still day, he may not cover it after dark. However, if one covered it while it was still day and it was uncovered on Shabbat, he is permitted to cover it even on Shabbat. One may fill a jug with cold water on Shabbat and place it beneath a pillow or a cushion to prevent it from getting warm.

גמ׳ אמר רב יהודה אמר שמואל: מותר להטמין את הצונן. אמר רב יוסף: מאי קמשמע לן? תנינא: ממלא אדם קיתון ונותן תחת הכר או תחת הכסת!

Talmud: Rav Yehuda said that Shmuel said: It is permitted to insulate the cold food on Shabbat to keep it cold. There is no concern that this will lead one to insulate hot food on Shabbat to keep it hot. Rav Yosef said: What is Shmuel teaching us with this statement? We already learned in our Mishnah: One may fill a jug with cold water on Shabbat and place it beneath a pillow or a mattress to prevent it from getting warm.