Mishkat al-Masabih 932
Abu Huraira reported God’s Messenger as saying:
If anyone would like to have the fullest measure granted him when he invokes blessings on us, the members of the prophetical family, he should say, “O God, bless Muhammad the ummi* prophet, his wives who are the mothers of the faithful, his offspring, and the people of his house as Thou didst bless the family of Abraham. Thou art indeed praiseworthy and glorious.” 

* This has commonly been explained as meaning “illiterate”, but it may mean “gentile”. Cf. Al-Qur’an; 7:157, 158.

Abu Dawud transmitted it.
وَعَنْ أَبِي هُرَيْرَةَ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَنْ سَرَّهُ أَنْ يَكْتَالَ بِالْمِكْيَالِ الْأَوْفَى إِذَا صَلَّى عَلَيْنَا أَهْلَ الْبَيْتِ فَلْيَقُلْ اللَّهُمَّ صَلِّ على مُحَمَّد وَأَزْوَاجِهِ أُمَّهَاتِ الْمُؤْمِنِينَ وَذُرِّيَّتِهِ وَأَهْلِ بَيْتِهِ كَمَا صَلَّيْتَ عَلَى آلِ إِبْرَاهِيمَ إِنَّكَ حُمَيْدٌ مَجِيدٌ» . رَوَاهُ أَبُو دَاوُد