In the story of the migration of the Prophet of Allah, sallallaahu ‘alayhi wa sallam, `Aa’ishah (the wife of the Prophet of Allah, sallallaahu ‘alayhi wa sallam) mentioned
“Seldom did the Prophet of Allah, sallallaahu ‘alayhi wa sallam, not come to the house of Abu Bakr either during the day or night, but when he, sallallaahu ‘alayhi wa sallam, was given permission to leave to Madinah, he came to our house at noon. Abu Bakr was informed of the Prophet’s coming, and said: ‘The Prophet of Allah, sallallaahu ‘alayhi wa sallam, has only come to us (at this time of the day) because something important happened.’
When the Prophet of Allah, sallallaahu ‘alayhi wa sallam, entered, he said: ‘Let those who are in your home leave.’ Abu Bakr said
‘O Messenger of Allah, these are my two daughters.’ He, sallallaahu ‘alayhi wa sallam, meant, `Aa’ishah and Asmaa’. So he, sallallaahu ‘alayhi wa sallam, said: ‘Did you have a feeling that I have been given permission to leave?’ Abu Bakr said: ‘I will accompany you, O Messenger of Allah.’ The Prophet of Allah, sallallaahu ‘alayhi wa sallam, responded: ‘You will accompany me.’ Abu Bakr then said: ‘O Messenger of Allah, I have two animals that I have prepared for travel, so take one of them. The Prophet of Allah, sallallaahu ‘alayhi wa sallam, responded: ‘I will take it and will pay its price.’”
Ibn Hajar (a scholar) said: “Ibn Is-Haaq (a scholar) added that the Prophet of Allah, sallallaahu ‘alayhi wa sallam, said: ‘I will not ride a camel that is not my possession.’ So Abu Bakr said: ‘Then it is yours,’ and the Prophet of Allah,sallallaahu ‘alayhi wa sallam, said: ‘No, but only with the condition that I pay the price that you purchased it for.’”
In the narration of Asmaa’ bint Abu Bakr (a woman Companion) that At-Tabaraani (a scholar) reported
the Prophet of Allah, sallallaahu ‘alayhi wa sallam, said: “Only on the condition that I pay the price needed to purchase it.” To which Abu Bakr said: “That condition is so, if you wish.”