It is narrated from Sayyiduna Abdur Rahman bin Abzi that he had the honor of offering prayer with the Prophet (ﷺ). The Prophet (ﷺ) would not say the complete takbeer while bowing for ruku and while raising his head.
Hadith Referenceمسند احمد / مسند المكيين / 15352
Hadith Gradingحکم دارالسلام:حديث ضعيف، أعله الأئمة النكارته، فقد تفرد به الحسن بن عمران، وهو مجهول، وقد اضطرب فى تعيين شيخه