Mukhtasar Muslim (Abridged) 2122 — Severity of differing

Narrated by Sayyiduna Jundub bin Abdullah Bajali (may Allah be pleased with him): The Messenger of Allah (peace and blessings of Allah be upon him) said: Recite the Qur'an as long as your hearts are in agreement with your tongues, and when there is a difference between your hearts and your tongues, then get up (stop reciting).