Why did the Messenger of Allah (peace and blessings be upon him) order Abu Bakr (may Allah be pleased with him) to lead the Companions (may Allah be pleased with them) in prayer during his illness, even though Ubayy ibn Ka'b (may Allah be pleased with him) was more memorized than he?

The questioner : He says:The questioner : Your Eminence, why did the Messenger of Allah (peace and blessings be upon him) order Abu Bakr (may Allah be pleased with him) to lead the Companions in prayer during his illness, even though Ubayy ibn Ka'b (may Allah be pleased with him) was more memorized than he?

The Shaykh : First, we require the questioner to prove what he claimed. Show me the evidence that Ubayy ibn Ka'b was more memorized than Abu Bakr (may Allah be pleased with him), who was constantly with the Messenger of Allah (peace and blessings be upon him) in a way that no other Companion was. He never lagged behind the Messenger, whether in residence, travel, war, or peace. In fact, he was alone with the Prophet (peace and blessings be upon him) in a place where no one else was ever with him. What is it? The Cave of Hira.
The student: The Cave of Thawr.

The Shaykh : Yes, the Cave of Thawr. The Cave of Hira is where the Messenger was alone in receiving revelation. This is the Cave of Thawr, which is on the road from Makkah to al-Madinah. He was alone with the Prophet (peace and blessings be upon him) in the Cave of Thawr; no other Companion was alone with him. So who claims that Ubayy ibn Ka'b was more memorized of the Book of Allah than he? The one who makes that claim must prove it with authentic transmission. Furthermore, memorizing the Qur'an in the era of the Companions was a form of memorization that entailed knowledge, for they did not pass ten verses without learning the knowledge and practice contained therein. There is no doubt that the most knowledgeable and most juristic of the Companions was Abu Bakr (may Allah be pleased with him). He was the most knowledgeable of the Companions regarding the Shari'ah of Allah, the most juristic of the Companions regarding the Shari'ah of Allah, and the most knowledgeable of the Companions regarding the condition of the Messenger of Allah. When he delivered a sermon on the pulpit in the last days of his life (peace and blessings be upon him) and said: This is what the Messenger said. Abu Bakr wept, and no one else wept. Now, the statement: "A servant among the servants of Allah was given a choice by Allah between living in this world as long as Allah willed for him to live, and meeting his Lord."
So he chose to meet his Lord. The word "servant" in its apparent meaning does not apply exclusively to the Messenger (peace and blessings be upon him), but why did Abu Bakr weep? Because he knew that the servant whom Allah gave the choice was the Messenger of Allah (peace and blessings be upon him). The narrator said: For this reason, the Prophet (peace and blessings be upon him) appointed him as the imam in prayer. This is from one aspect. From another aspect, it is an indication that he is the successor after him, because if he succeeded him in leading his community in prayer, which is the greatest pillar of Islam, then in other matters of religion and worldly affairs, it is even more so. Do you understand, people? So, for this reason, he appointed him as the leader of the community in a gathering broader and greater than this, which was leading the people in Hajj in the year nine. The leader of the people in that Hajj was Abu Bakr, and the Prophet (peace and blessings be upon him) appointed 'Ali ibn Abi Talib (may Allah be pleased with him) to accompany him. This is the reason the Prophet (peace and blessings be upon him) chose Abu Bakr (may Allah be pleased with him) over the other Companions. The intended meaning of "the trustworthy one" indicates that the time is up. Your clock is not set; you looked at it before it passed. We will give you one minute, there is no harm in one minute.