(Good)
4. The commanders of the army battalions—ʿAmr ibn al-ʿĀṣ, Khālid ibn al-Walīd, Shuraḥbīl ibn Ḥasnah, and Yazīd ibn Abī Sufyān—related:

The Messenger of Allah ﷺ saw a man who was not completing his bowing and was pecking through his prostration while praying. He said, “If this man were to die in this condition, he would die upon a way other than the religion of Muhammad. He pecks at his prayer just as a crow pecks at blood. The one who does not perfect his bowing and pecks in his prostration is like a starving person who eats one or two dates—they do nothing to satisfy him.”

Reported by al-Ājurri in al-Arbaʿīn and by al-Bayhaqi with a good chain. Al-Mundhiri added that it was also transmitted by al-Ṭabarāni in al-Kabīr, by Abū Yaʿlā with a good chain, and by Ibn Khuzaymah in his Ṣaḥīḥ.

(Authentic)
5. Ṭalq ibn ʿAlī narrated that the Messenger of Allah ﷺ said:

“Allah does not look at the prayer of a servant who does not straighten his spine between its bowing and prostration.”

Recorded by Ahmad, al-Ṭabarāni in al-Kabīr, and al-Ḍiyāʾ al-Maqdisī in al-Mukhtārah. Its chain is authentic, and it has a corroborating narration in the Musnad whose transmitters are all reliable. Al-Ḥāfiẓ al-ʿIrāqī declared it authentic in Takhrīj al-Iḥyāʾ, and al-Mundhiri said, “Its chain is sound.” ⦗118⦘