What is the ruling on the saying: "No greetings over food"?

There is no explicit evidence from the Qur’an or Sunnah (definition) that prohibits greeting someone who is eating, and the general principle is that greeting and returning a greeting are permissible. Some jurists have mentioned an exception for greeting someone who is eating or drinking, but they have not provided any evidence for this. Based on the principle of istiṣḥāb (presumption of continuity), greeting someone who is eating is permissible, and they are obliged to return the greeting, until there is evidence that specifies an exception to this general principle.