Once, Hazrat ‘Aa’ishah (radhiyallahu ‘anha) spoke to her nephew ‘Urwah (rahimahullah) and said,
“O my nephew! Both your fathers (your father and your maternal grandfather), Hazrat Zubair (radhiyallahu ‘anhu) and Hazrat Abu Bakr (radhiyallahu ‘anhu), were among the group of Sahaabah regarding whom Allah Ta‘ala spoke about in the following verse in regard to the battle of Uhud.
ٱلَّذِينَ ٱسْتَجَابُوا لِلَّـهِ وَٱلرَّسُولِ مِن بَعْدِ مَآ أَصَابَهُمُ ٱلْقَرْحُ لِلَّذِينَ أَحْسَنُوا مِنْهُمْ وَٱتَّقَوْا أَجْرٌ عَظِيمٌ ﴿١٧٢﴾
Those who answered the call of Allah and the Messenger, even after being wounded, for those among them who do good and refrain from wrong is a great reward
Hazrat Aa’ishah (radhiyallahu ‘anha) further mentioned, “When difficulty had befallen Rasulullah (sallallahu ‘alaihi wasallam) on the Day of Uhud (due to the disbelievers attacking the Muslims and wounding Rasulullah (sallallahu ‘alaihi wasallam)) and the disbelievers had departed, Rasulullah (sallallahu ‘alaihi wasallam) feared that they may return (and try to attack the Muslims once more). Hence, Rasulullah (sallallahu ‘alaihi wasallam) announced, “Who will go after them (i.e. the disbelievers)?”
On hearing this announcement, seventy Sahaabah (radhiyallahu ‘anhum) of Rasulullah (sallallahu ‘alaihi wasallam) answered the call and went in pursuit of the disbelievers. (The disbelievers were intending to return, but on hearing that the Sahaabah (radhiyallahu ‘anhum) had come in pursuit of them, they abandoned their idea of returning and fled). Among the seventy sahaabah were Hazrat Abu Bakr (radhiyallahu ‘anhu) and Hazrat Zubair (radhiyallahu ‘anhu).”
(Saheeh Bukhaari #4077, Fat-hul Baari 7/432)