Al-Qasim bin Muhammad (may Allah have mercy on him) said: Abdullah bin Abi Bakr (may Allah be pleased with them both) was struck by an arrow on the day of al-Ta'if, and he died forty days after the death of the Messenger of Allah (peace and blessings be upon him). He mentioned the story, (saying) that a delegation of Thaqif came to him (Abu Bakr), and this arrow was still with him. He brought the arrow out before the delegation and said: Does any of you recognize this arrow? Sa'id bin Ubayd of Banu al-Ajlan said: I shaped this arrow, and I am the one who shot it. So Abu Bakr (may Allah be pleased with him) said: This arrow killed Abdullah bin Abi Bakr (may Allah be pleased with them both). All praise is for the One who honoured him by your hand and did not disgrace you by his hand, for that is better for both of you.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18191