Al-Kāfi - Volume 2 > Asking Favors from Allah for the Holy Prophet, Muhammad and his Family, recipient of divine supreme covenant
Hadith #9

9ـ أَبُو عَلِيٍّ الأشْعَرِيُّ عَنْ مُحَمَّدِ بْنِ حَسَّانَ عَنْ أَبِي عِمْرَانَ الأزْدِيِّ عَنْ عَبْدِ الله بْنِ الْحَكَمِ عَنْ مُعَاوِيَةَ بْنِ عَمَّارٍ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ مَنْ قَالَ يَا رَبِّ صَلِّ عَلَى مُحَمَّدٍ وَآلِ مُحَمَّدٍ مِائَةَ مَرَّةٍ قُضِيَتْ لَهُ مِائَةُ حَاجَةٍ ثَلاثُونَ لِلدُّنْيَا وَالْبَاقِي لِلآخِرَةِ.

9. Abu Ali al-Ash’ari has narrated from Muhammad ibn Hassan from abu ‘Imran al-Azdi from ‘Abd Allah ibn al-Hakam from Mu’awiyah ibn ‘Ammar from abu ‘Abd Allah (a.s.) who has said the following: “Whoever says, ‘O Lord, grant favors to Muhammad and his family, one hundred times one hundred of his wishes will be granted, thirty of them in this world and the rest in the next life.’”