The Strongest of the Companions in Eemaan
Taken from the book
‘The Life of the Greatest Man After the Prophets & Messengers:
Abu Bakr as-Siddeeq’
Muhammad Uthmaan al-Anjaaree
Abbas Abu Yahya
1- On the authority of Abu Huraira –Radi Allaahu anhu
So the people said: ‘Subhana Allaah a cow spoke!’
The Messenger of Allaah –sallAllaahu alayhi wa sallam– said: ‘Indeed I believe this, me and Abu Bakr and Umar.’ Even though they were not present.
The Messenger –sallAllaahu alayhi wa sallam- continued: ‘While a man was with some sheep, suddenly a wolf attacked them and took away one sheep from amongst them. The shepherd called the sheep as if trying to rescue it from the wolf.
Thewolf said to him: ‘You want to rescue it from me, so who will protectit on the day when the predatory animal comes, the day when it has noshepherd other than me.’
So the people said: ‘Subhana Allaah, a wolf spoke.’
The Messenger of Allaah –sallAllaahu alayhi wa sallam– said: ‘Indeed I believe this, me and Abu Bakr and Umar.’ Even though they were not present. 
* Hafidh Ibn Hajr said: ‘It is possible that the Prophet –sallAllaahu alayhi wa sallam- said that due to what he knew of their overwhelming Eemaan and the strength of their certainty. 
2- On the authority of Abu Huraira –Radi Allaahu anhu– who said the Messenger of Allaah –sallAllaahu alayhi wa sallam– said: There was a man walking wearing a garment whose appearance impressed his own self. Allaahmade the ground swallow him up and he kept tumbling down into it untilthe Day of Judgement.’ Abu Bakr and Umar testified to it, while AbuBakr and Umar were not present.
3- On the authority of Ayyoob who said: that AbdurRahmaan bin Abu Bakr said to his father (Abu Bakr):
I saw you on the day of Uhud but I avoided you. So Abu Bakr said: ‘if I had seen you I would not have avoided you.’ 
4- On the authority of Umar: ‘If the Eemaan of Abu Bakr was weighed against the Eemaan of the people of the earth, the Eemaan of Abu Bakr would outweigh the others.’ 
5-On the authority of Aa’ishah who said: ‘I swear by Allaah that Abu Bakrleft drinking alcohol in pre-Islaamic times and he did not doubt inAllaah after having accepted Islaam.’ 
6- On the authority of Ibn Shihaab who said: ‘From the excellence of Abu Bakr is that he never ever doubted in Allaah – Azza wa Jal – even for an hour.’ 
7-On the authority of Bakr bin Abdullaah who said: ‘Indeed the people didnot prefer Abu Bakr because he would pray and fast more than them,rather they preferred him due to something his heart.’ 
‘Aboo Bakr did not have excellence over the people ( lam yafdulin-naasa) on
account of praying and fasting more than them, but rather he had excellence over them on
account of something which was in his heart.’
-And I think the reference should be
Narrated by Imam Ahmad in ‘Fadail as-Sahabah’ with this wording (1:141) no. 118 .
[Taken from the book: ‘The Life of the Greatest Man After the Prophets & Messengers: Abu Bakr as-Siddeeq’ P.190-191]
 Narrated by Bukhari no.3285 and Muslim (15/156 Nawawee).
 Fath al-Bari 7/18
 Narrated by Imam Ahmad in ‘Fadail as-Sahabah’ with this wording (1:112) no. 92. Its researcher WaseeAllaah bin Muhammad Abbas said: Its Isnaad is Saheeh.
Narrated by Bukhari no.5453 & Muslim (14/63 Nawawee). By AbdurRazzaq (11:82) no. 19983 but they did not mention ‘Abu Bakr and Umar testified to it.’ This extra wording was mentioned by Musadad as in ‘al-Mutalib al-‘Aaleeyah’ (4:35)
Narrated by Ibn Abee Shaybah (14:408) no. 18642 and Ibn Hajr said in‘Talkhees al-Habeer’ (4:101): its narrators are trustworthy along withIrsaal.
 Narrated by al-Bayhaqi in ‘al-Jamia’ lashu’ab al-Eemaan’ (1:18) and its narrators are trustworthy.
 Narrated by Abu Na’eem in ‘al-Ma’arifah’ 91;179) no. 108
 Narrated by Abdullaah in his Zawaid of al-Fadail (1:126) no. 96. Its researcher WaseeAllaah bin Muhammad Abbas said: Its Isnaad is Saheeh till az-Zuhri.
 Narratedby Imam Ahmad in ‘Fadail as-Sahabah’ with this wording (1:114) no. 118Its researcher WaseeAllaah bin Muhammad Abbas said: Its Isnaad isSaheeh.