أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا يَحْيَى، - يَعْنِي ابْنَ سَعِيدٍ الْقَطَّانَ - عَنْ يَحْيَى، - يَعْنِي ابْنَ سَعِيدٍ الأَنْصَارِيَّ - قَالَ حَدَّثَنِي ذَكْوَانُ أَبُو صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي لَمْ أَتَخَلَّفْ عَنْ سَرِيَّةٍ وَلَكِنْ لاَ يَجِدُونَ حَمُولَةً وَلاَ أَجِدُ مَا أَحْمِلُهُمْ عَلَيْهِ وَيَشُقُّ عَلَيْهِمْ أَنْ يَتَخَلَّفُوا عَنِّي وَلَوَدِدْتُ أَنِّي قُتِلْتُ فِي سَبِيلِ اللَّهِ ثُمَّ أُحْيِيتُ ثُمَّ قُتِلْتُ ثُمَّ أُحْيِيتُ ثُمَّ قُتِلْتُ ‏"‏ ‏.‏ ثَلاَثًا ‏.‏

It was narrated from Abu Hurairah that the Prophet (PBUH) said: "Were it not that it would be too difficult for my Ummah, I would not have stayed behind from any expedition. But they could not find mounts, and I could not find any mounts for them, and it would be too hard for them to stay behind when I went out. And I wish that I could be killed in the cause of Allah, then brought back to life, then killed, then brought back to life, then killed," three times. Translation Not Available

Book Ref: Sunan An Nisai Book 25 Hadith 3151
Web Ref:  Sunan An Nisai Vol 1 Book 25 Hadith 3153