The Messenger of Allah ﷺ said, "Eat olive oil and anoint yourselves with it, for it comes from a blessed tree."In another wording, "Use olive oil as a condiment with your food."
قال رسول الله ﷺ: كلوا الزيت، وادهنوا به، فإنه من شجرة مباركة. وفي لفظ: ائتدموا بالزيت.
Tirmidhi (1851), Ibn Majah (3319), Hakim (4/122), and Diya Maqdisi in al-Mukhtarah (82, 83) all narrated it through routes from Abdul-Razzaq, from Maamar, from Zayd bin Aslam, from his father, from Umar bin Khattab, and he mentioned it. The wording is Tirmidhi's, while the other wording belongs to Ibn Majah and Hakim.The preserved version from the narration of Abdul-Razzaq is the mursal one, but it has come through another route as connected (mawsul) with Tahawi in Mushkil al-Athar (4448), though there is weakness in its chain. With this, the hadith rises to the level of hasan. The discussion of it is treated at length in the book on foods.