The Prophet ﷺ said, "A man from the people of Paradise will be brought forward on the Day of Resurrection, and Allah will say, 'Son of Adam, how did you find your dwelling?'He will reply, 'My Lord, the finest of dwellings.'Allah will say, 'Ask and wish for whatever you desire.'He will say, 'I ask and wish only that You return me to the world so that I may be killed in Your cause ten times over,' because of what he sees of the excellence of martyrdom."
حدثنا عبد الرحمن يعني ابن مهدي عن حماد بن سلمة عن ثابت
عن النبي ﷺ قال يؤتى بالرجل من أهل الجنة يوم القيامة فيقول الله عز وجل يا ابن آدم كيف وجدت منزلك فيقول يا رب خير منزل فيقول سل وتمنه فيقول ما أسأل وأتمنى إلا أن تردني إلى الدنيا فأقتل في سبيلك عشر مرات لما يرى من فضل الشهادة
Its isnad is sahih. It has already been mentioned in similar wording, and it appears in Nasai, 6/33, no. 3153, in the chapter on jihad, on the merit of being killed in the cause of Allah, and in Hakim, 2/75, who graded it sahih, and Dhahabi agreed with him.