Is saying "I am an Arab" by someone who does not know their ancestors considered a lie against the father and a sin, by analogy with the Hadith: "Indeed, among the greatest fabrications is for a man to claim a lineage other than that of his father"?

If a person describes himself as an Arab because he lives in Arab lands and speaks their language, there is no sin upon him, even if his ancestors were not Arabs. Scholars have classified Arabs into 'Musta'ribah' (Arabized Arabs), who were originally non-Arabs but entered the Arab fold and spoke their language. The term 'Arab' originally applies to those who combine three characteristics: their language is Arabic, they are descendants of Arabs, and their dwelling place is the Arabian Peninsula. The Salaf (early Muslims) stated that whoever speaks Arabic is an Arab, and whoever is born into Islam is an Arab. Therefore, it is permissible for someone who speaks Arabic and lives in Arab lands to call himself an Arab, even if he does not know his ancestors or if they were non-Arabs.