Hadith #1642 (Jami' al-Tirmidhi)
Book: The Book on Virtues of Jihad
Narrator(s): Talb bin Hjyr طالب بن حجير

From his father that the Messenger of Allah (ﷺ) said: “The souls of the martyrs are in green birds, suspended from the fruit of Paradise, or the trees of Paradise.”
 This Hadith is Hasan Sahih.

Source: https://parallelquran.com/hadith/jami-al-tirmidhi-1642/