What is the correct wording of the Prophet’s (PBUH) hadith: "I am leaving among you that which, if you hold fast to it, you will never go astray after me, ever"? Is it "the Book of Allah and my Sunnah" or "and my progeny"?

Both phrases, "My Sunnah" and "My 'Itrah (Progeny)," are correct and established, and each has its own meaning. "My Sunnah" means adhering to it and being guided by what is in it, while "My 'Itrah" means that being guided by the commands of the Qur'an and the guidance and conduct of the 'Itrah leads to not going astray. Al-Qurtubi recommends respecting, appreciating, and loving the Household of the Prophet (Ahl al-Bayt). As for what is meant by "His 'Itrah" here, it refers to the righteous scholars who do not abandon the Qur'an.