Is saying "I don't have it" considered a lie if a person is asked about money they don't currently possess but will acquire later after the conversation?

The statement "I do not have" is a 'Tawriyah' (a double entendre), and it is not a lie. Rather, it is the use of a word that carries two meanings: one that the questioner understands, and the other that is truly intended. 'Tawriyah' is permissible when there is a need for it, disliked when there is no need, and becomes forbidden if it leads to injustice or the denial of another's right.