It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever says: 'Jazallahu 'anna Muhammadan bima huwa ahluh' (May Allah Almighty reward Muhammad (peace and blessings be upon him) on our behalf with what he deserves), has wearied seventy recording angels for a thousand mornings."
Only Ja'far bin Muhammad (may Allah have mercy on him) narrated this hadith from Ikrimah (may Allah have mercy on him), and only Mu'awiyah bin Salih (may Allah have mercy on him) from Ja'far (may Allah have mercy on him), while Hani' bin al-Mutawakkil (may Allah have mercy on him) is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الألف / 235
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 11509»