This complete hadith is authentic; there is no reason to declare the mentioned words as irregular, because this is not such an addition by a trustworthy narrator that would negate the narration of other trustworthy narrators. The words of the trustworthy narrators' narration "وَأَشَارَباِلسَّبَّابَۃِ" and the words of Zaidah bin Qudamah's narration "ثُمَّرَفَعَإِصْبَعَہُفَرَأَیْتُہُیُحَرِّکُہَایَدْعُوْبِہَا" have no contradiction whatsoever. Imam Albani has also declared it authentic.
Hadith Referenceالفتح الربانی / أبواب صفة الصلاة / 1789
Hadith Gradingمحدثین:صحیح
Hadith Takhrij«حديث صحيح دون قوله: فرأيتهيحركھايدعو بھا فھو شاذ انفرد به زائدة بن قدامة من بين اصحاب عاصم بن كليب ترقیم بيت الأفكار الدولية: 19075»