Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: The Prophet (peace and blessings be upon him) used to raise his hands at the takbir for going into bowing and at the takbir for going into prostration.
Al-Tabarani recorded it in al-Mu'jam al-Awsat. It is also mentioned in the Sahih, but without mention of the takbir for prostration. The chain of this report is sahih (authentic).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2590
Hadith Gradingمحدثین:إسنادہ صحیح۔
Hadith Takhrij«أخرجه المعجم الأوسط للطبراني برقم: 16»