Sunan Ibn Majah, Volume 4, Book 29, Hadith 3319 (DarusSalam) ⓘ
It was narrated from ‘Umar that the Messenger of Allah said: ‘Season (your food) with olive oil and anoint yourselves with it, for it comes from a blessed tree.”
حَدَّثَنَا الْحُسَيْنُ بْنُ مَهْدِيٍّ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَنْبَأَنَا مَعْمَرٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ أَبِيهِ، عَنْ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " اِئْتَدِمُوا بِالزَّيْتِ وَادَّهِنُوا بِهِ فَإِنَّهُ مِنْ شَجَرَةٍ مُبَارَكَةٍ " .
also referenced under: Hadith 3319 (Reference) & Book 29, Hadith 3444 (In-Book)