Masruq said

We asked 'Abdallah b. Mas'ud about this verse, “Do not consider those who have been killed in Allah’s path to be dead; nay, they are alive in the presence of their Lord and are being supplied with provision" (Al-Qur’an; 3:169). He replied that he had asked about that, and the Prophet (ﷺ) said, "Their spirits are in the crops of green birds which have lamps suspended from the Throne, which go where they wish in paradise and then return to those lamps. Their Lord looks down on them and asks whether they desire anything, and they ask in reply what they could wish when they can go where they like in paradise. He does that with them three times, and when they see that they will not be left alone without asking something, they tell their Lord that they wish Him to return their spirits to their bodies so that they may be killed in His path once again. Then when He sees that they lack nothing they are left without further questioning." Muslim transmitted it.