1,042. Asking a Merchant for Merchandise on Yom Tov
Shvisas Yom Tov 4:21
On yom tov, one may not tell a butcher, "Give me a dinar worth of meat." Rather, one should say, "Give me a portion" or "...half a portion." After yom tov, they calculate its value. Similarly, one may not take a certain measure or a certain weight of merchandise from a shopkeeper. Instead, he asks the shopkeeper to fill the container and he pays him after yom tov for its value. Even if the container is used for measuring, he may fill it on yom tov so long as he does not discuss any particular volumes.
Shvisas Yom Tov 4:22
A cook may measure spices and add them to a dish to keep it from spoiling but a housewife may not measure flour for her dough, nor may a man measure the feed he puts before his animal. Rather, he approximates the measure and uses that.