Source: Fatāwā Amunpuri by Shaykh Ghulam Mustafa Zaheer Amunpuri
Is the addition (ziyādah) of a trustworthy narrator accepted?
Yes, the addition of a trustworthy narrator is accepted.
✔ Imam al-Bukhārī رحمه الله:
“The addition is accepted.”
(صحيح البخاري, no. 1483)
✔ Imam al-Dāraquṭnī رحمه الله:
“The addition of a trustworthy narrator is accepted according to us (the Hadith scholars).”
(الإلزامات والتتبع: 370)
✔ Hafiz al-Bayhaqī رحمه الله:
“The addition of a trustworthy narrator is accepted, provided that it does not contradict the narration of a group of reliable narrators.”
(معرفة السنن والآثار: 3/268)
Conclusion:
The principle of Hadith scholarship is that the ziyādah (addition) of a trustworthy narrator is accepted, as long as it does not conflict with the established narrations of other trustworthy narrators.
◈ Question:
Is the addition (ziyādah) of a trustworthy narrator accepted?
◈ Answer:
Yes, the addition of a trustworthy narrator is accepted.
❀ Statements of the Scholars
✔ Imam al-Bukhārī رحمه الله:
“The addition is accepted.”
(صحيح البخاري, no. 1483)
✔ Imam al-Dāraquṭnī رحمه الله:
“The addition of a trustworthy narrator is accepted according to us (the Hadith scholars).”
(الإلزامات والتتبع: 370)
✔ Hafiz al-Bayhaqī رحمه الله:
“The addition of a trustworthy narrator is accepted, provided that it does not contradict the narration of a group of reliable narrators.”
(معرفة السنن والآثار: 3/268)

The principle of Hadith scholarship is that the ziyādah (addition) of a trustworthy narrator is accepted, as long as it does not conflict with the established narrations of other trustworthy narrators.