Is it permissible to eat from the fruits of a lemon tree upon which vomit, possibly containing sorcery, was poured, and does that affect family members?

The jurists differed regarding the ruling on vomit, with most considering it impure. Al-Shawkani and Ibn Uthaymeen, however, held it to be pure. Based on the opinion that it is impure, vomit mixed with water used to irrigate a plant does not affect the purity of its fruit, because the default state of things is permissibility, and nothing is forbidden except with evidence. One should not pay attention to superstitions like magic and the like.