حَدَّثَنَا أَحْمَدُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا أَبُو دَاوُدَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ بُدَيْلٍ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، أَنَّ عُمَرَ، - رضى الله عنه - جَعَلَ عَلَيْهِ أَنْ يَعْتَكِفَ فِي الْجَاهِلِيَّةِ لَيْلَةً أَوْ يَوْمًا عِنْدَ الْكَعْبَةِ فَسَأَلَ النَّبِيَّ صلى الله عليه وسلم فَقَالَ " اعْتَكِفْ وَصُمْ " .
Narrated Abdullah ibn Umar: Umar (may Allah be pleased with him) took a vow in the pre-Islamic days to spend a night or a day in devotion near the Ka'bah (in the sacred mosque). He asked the Prophet (PBUH) about it. He said: Observe i'tikaf (i.e. spend a night or a day near the Ka'bah) and fast. Translation Not Available
Book Ref: Sunan Abi Dawud Book 14 Hadith 2474
Web Ref: Sunan Abi Dawud Book 13 Hadith 2468