744. A Non-Jew Who Brought Food

101:3 If a non-Jew brought fish or fruit on the first day of yom tov and there is reason to believe that they may have been caught or picked on that day, or brought from outside the Shabbos boundary (techum), then the fish or fruit may not be handled on that day but they are permitted that night. (If the non-Jew brought them for himself, then the Jew may use them immediately – Mishnah Brurah 325:25.) If the non-Jew knows the Jew and gives him the items without discussing the price, the Jew may take them and eat them except on Rosh Hashana. Since both days of Rosh Hashana are legally treated as if they were one long day, then even if the items were brought on the first day, they are still prohibited on the second day. (Such items would also be prohibited on a Shabbos that follows a yom tov because of the problem of preparing on yom tov for Shabbos – MB 515:25).

101:4
If the non-Jew brought something for the Jew to trade or to sell to him, one should not use it on the second day of yom tov, either. However, if yom tov falls on Thursday and Friday and the non-Jew brought the item on Thursday, then, if really necessary, one may handle the item on Friday and cook it in honor of Shabbos. Even this, however, is still prohibited on the two days of Rosh Hashana.