Sayyidah Aishah Siddiqah (may Allah be pleased with her) narrates this as a marfu' hadith: (The Prophet (peace and blessings be upon him) said:) "The death of a scholar is a breach in Islam that will not be closed as long as night and day alternate."
Al-Bazzar recorded it. Its chain mentions that Muhammad bin Abd al-Malik narrated it from al-Zuhri; al-Bazzar said: This man narrates hadith in which he is not corroborated, and this hadith is one of them.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب العلم / 984