Narrated Abu Barza:
Allah’s Apostle disliked to sleep before the ‘Isha prayer and to talk after it.
Sleeping before ‘Isha prayer won’t let you sleep after it, so quit it. :P
Talking after ‘Isha prayer is disliked when it’s in vain. When we sleep, our spirits (arwaah) leave our bodies. And according to a Hadith, they ascend towards Allah (SWT). He keeps whichever ruh He wills and sends back the rest. That’s how people die in their sleep. Anyway, we must prepare for our death every night. Imagine that you’ll be meeting Allah (SWT) and prepare accordingly. What would you want your last ‘amal to be? Vain talk or prayer?