Abdul-Hamid bin Abdul-Rahman invited Musa bin Talha to the wedding feast he held for his son and asked him, "Abu Isa, what has reached you concerning the prayer for blessings upon the Prophet ﷺ?"Musa replied, "I asked Zayd bin Kharija about the prayer for blessings upon the Prophet ﷺ, and Zayd said, 'I myself asked the Messenger of Allah ﷺ, saying, How are we to send blessings upon you?' He answered, 'Pray and strive in supplication, then say, O Allah, bless Muhammad and the family of Muhammad as You blessed Ibrahim. Indeed, You are Praiseworthy and Glorious.'"
حدثنا علي بن بحر حدثنا عيسى بن يونس حدثنا عثمان بن حكيم
أن عبد الحميد بن عبد الرحمن دعا موسى بن طلحة حين عرس على ابنه فقال يا أبا عيسى كيف بلغك في الصلاة على النبي ﷺ فقال موسى سألت زيد بن خارجة عن الصلاة على النبي ﷺ فقال زيد إني سألت رسول الله ﷺ بنفسي فقلت كيف الصلاة عليك قال صلوا واجتهدوا ثم قولوا اللهم بارك على محمد وعلى آل محمد كما باركت على إبراهيم إنك حميد مجيد
Its isnad is sahih. Khalid bin Salama bin Aas bin Hisham Makhzumi, known as Faafaa, is trustworthy. He was deemed trustworthy by Ahmad, Ibn Main, Ibn Madini, and others. Nasai narrated the hadith 1:190 in abbreviated form through Yahya bin Saeed Umawi from Uthman bin Hakeem.Bukhari narrated it in Al-Kabir, in the biography of Zayd, through Abdul-Wahid from Uthman bin Hakeem, and also through Marwan from Uthman, then said, "Isa bin Yunus and Yahya bin Saeed bin Aban corroborated him."Hafiz said in Tahdheeb 3:409, "There is disagreement about it going back to Musa bin Talha," meaning what Ahmad narrated in the Musnad of Talha, 1396, through Uthman bin Mawhab from Musa bin Talha from his father. We have already pointed there to Nasai's narration of it as well.This is not a disagreement or a defect, for Musa bin Talha heard the hadith from his father and from Zayd bin Kharija, and the narrators are trustworthy in both routes.This hadith is found in Usd al-Ghaba 2:227, transmitted through the Musnad with this isnad.