Reference: Siyar A’laam an-Nubalaa v5 p189
said:
I entered upon al-Jarraah, and he raised his hands, and [likewise] the leaders [around him too] raised their hands – and they remained [like this] for a long while. He (al-Jarraah) then said to me:
‘O Abaa Yahyaa, do you know what we were doing (supplicating for)?’
I replied: ‘No; I found you all intensely engaged [in supplication], so I raised my hands [in supplication] with you all.’
He (al-Jarraah) said: ‘We asked Allaah to bless us with martyrdom.’
And by Allaah, none of them remained in that battle until each one of them attained martyrdom.
