Sahih Bukhari
Virtues of the Quran
Volume: 006 / Book Number: 061 / Hadith Number: 581
Narrated Jundub:
The Prophet said, "Recite (and study) the Quran as long as you agree about its interpretation, but when you have any difference of opinion (as regards its interpretation and meaning) then you should stop reciting it (for the time being)'