Hadith 34:92
Malik narrated to us, he said: Mas'ud ibn Sa'd narrated to us, from Abu Ishaq, from Nafi', from Ibn Umar, he said: The first person to gather the people for prayer in Ramadan was Umar ibn al-Khattab, may Allah be pleased with him. He gathered them behind Ubayy ibn Ka'b.
حدثنا مالك قال حدثنا مسعود بن سعد عن أبي إسحاق عن نافع عن بن عمر قال أول من جمع الناس على الصلاة في رمضان عمر بن الخطاب رضي الله عنه جمعهم على أبي بن كعب