Assalamu Alaykum
Historical facts from both Shi'a and Sunni sects confirm that Imam Ali(as) is the ONLY person to have ever given away charity while bowing. Shaykh al-Islam Muhammad Tahir-ul-Qadri states that MOST of the Sunni hadith scholars record that the Verse was revealed about Imam Ali (as):
http://www.minhajbooks.com/english/control/btext/cid/2/bid/248/btid/761/read/txt/Hadith%2021%20to%2030-The%20Ghadir%20Declaration.html
Al-Sharif al-Jurjani, a Sunni scholar, also states in his Sharh al-Mawaqif, vol. 8, p. 360:
وقد أجمع أئمة التفسير على أنّ المراد بـ ( الذين يقيمون الصلاة ) إلى قوله تعالى ( وهم راكعون * علي فإنه كان في الصلاة راكعاً فسأله سائل فأعطاه خاتمه فنزلت الآية
The (Sunni) Imams of Tafsir have reached a consensus that the phrase “those who perform As-Salat” up to “while they bow” was revealed about Ali because while he was in Salat, a beggar begged, and he gave him his ring, and this Verse was then revealed.
Another Sunni scholar, Sa’d al-Din al-Taftazani, in his Sharh al-Maqasid, vol. 5, p. 170, also states:
نزلت في علي بن أبي طالب – رضي الله عنه – حين أعطى السائل خاتمه وهو راكع في صلاته
The Verse was revealed in favour of Ali ibn Abi Talib, may Allah be pleased with him, when he gave his ring in charity, while bowing in Salat.
Alaudin Ali ibn Muhammad al-Hanafi al-Qushiji al-Samarqandi, in his Sharh Tajrid al-Itiqad, p. 368, also states:
أنها نزلت باتفاق المفسرين في حق علي بن أبي طالب حين أعطى السائل خاتمه وهو راكع في صلاته
There is a CONSENSUS among the (Sunni) exegetes that the Verse was revealed about Ali ibn Abi Talib when he gave his ring in charity to a beggar, while bowing in his Salat.
Qadi Imduddin al-Ayji also states in his al-Mawaqif fi Ilm al-Kalam, p. 405:
وأجمع أئمة التفسير أنّ المراد علي
There is a CONSENSUS among the (Sunni) Imams of Tafsir that it was revealed about Ali.
Abd al-Karim al-Khatib states in his book Tafsir al-Qur’an li al-Qur’an, vol. 5, p. 1124:
قد ذهب كثير من المفسرين أن قوله تعالى ( الذين يقيمون الصلاة ويؤتون الزكاة وهم راكعون ) مراد به علي بن أبي طالب كرّم الله وجهه
Imam al-Suyuti, in his Lubab al-Nuqul, vol. 1, p. 93, states:
قوله تعالى : ( إنما وليكم الله ) الآية ، أخرج الطبراني في الأوسط بسند فيه مجاهيل عن عمّار بن ياسر قال : وقف على علي بن أبي طالب سائل وهو راكع في تطوع فنزع خاتمه فأعطاه السائل فنزلت : ( إنما وليكم الله ورسوله ) الآية ، وله شاهد قال عبد الرزاق حدثنا عبد الوهاب بن مجاهد عن أبيه عن ابن عباس ( إنما وليكم الله ورسوله ) الآية ، قال : نزلت في علي بن أبي طالب ، وروى ابن مردويه عن وجه آخر عن ابن عباس مثله ، وأخرج أيضاً عن علي مثله ، وأخرج ابن جرير عن مجاهد وابن أبي حاتم عن سلمة بن كهيل مثله ، فهذه شواهد يقوي بعضها بعضاً
Concerning His Statement "Your Wali is Allah", al-Tabarani recorded in his al-Awsat through a chain containing unknown narrators from Ammar ibn Yasir, who said: “A beggar came up to Ali and stood beside him. He was bowing in prayer. He (the beggar) pulled out his ring and he gave the ring to the beggar. Then the Verse was revealed.” THIS REPORT HAS CORROBORATION. Abd al-Razzaq said: narrated to us Abd al-Wahab ibn Mujahid, from his father (Mujahid), from Ibn Abbas, who said: “ (Verily, Your Wali is Allah and the Messenger ...) was revealed about Ali ibn Abi Talib. Ibn Mardawayh has also recorded THROUGH ANOTHER CHAIN the same statement from Ibn Abbas. He again recorded a similar statement from Ali. Ibn Jarir narrated the same opinion from Mujahid, while Ibn Abi Hatim also narrated the same opinion from Salamah ibn Kuhayl. These reports are witnesses (for one another), each STRENGTHENING the other.
Imam al-Tha’labi, in his Al-Kashaf wa al-Bayan, vol. 4, p. 80 states:
قال ابن عباس، وقال السدي، وعتبة بن حكيم، وثابت بن عبدالله: إنما يعني بقوله: {وَالذِينَ آمَنُوا الذِينَ يُقِـيمُونَ الصَّـلاةَ} الآية، علي بن أبي طالب (رضي الله عنه) مرّ به سائل، وهو راكع في المسجد وأعطاه خاتمه
Ibn Abbas, al-Suddi, Utbah ibn Hakim, and Thabit ibn Abdullah said: <<… those who believe, those who perform As-Salat…>> refers to Ali ibn Abi Talib. A beggar came to him, while he was bowing during Salat, and he gave the beggar his ring.”
Ibn al-Jawzi, in his Zad al-Masir, vol. 2, p. 292, also states:
و به قال مقاتل، وقال مجاهد: نزلت في علي بن أبي طالب تصدق وهو راكع
This is what Maqatil and Mujahid both said: The Verse was revealed about Ali ibn Abi Talib. He gave charity while bowing.