Reference for Shabbat 1:5
בֵּית שַׁמַּאי אוֹמְרִים, אֵין שׁוֹרִין דְּיוֹ וְסַמְמָנִים וְכַרְשִׁינִים, אֶלָּא כְּדֵי שֶׁיִּשּׁוֹרוּ מִבְּעוֹד יוֹם. וּבֵית הִלֵּל מַתִּירִין:
Beth Shammai say: Ink [i.e., dyes from which ink is made], dyes [for paints] and karshinim [an animal food, which they would first soak], are not soaked (on Sabbath eve), unless they be soaked (i.e., fully softened) while it is yet day. [Beth Shammai hold that one is exhorted in respect to the resting of his vessels (on the Sabbath), just as he is exhorted in respect to the resting of his beast. And this is, likewise, the reason for (1:6) "Bundles of flax are not placed into the oven," and (Ibid.): "Nets are not spread." As to a lamp burning on the Sabbath and a pot on the stove, where Beth Shammai concede (that it is permitted), this is where he renounces ownership of the vessels, in which instance he is not commanded in respect to their resting.] And Beth Hillel permit it [when the water was put in while it was still day, even though they undergo soaking on the Sabbath, Beth Hillel holding that a man was exhorted in respect to the resting of his beast on the Sabbath, where there is distress for the animal (in not resting), but not in respect to the resting of vessels.]