Sahih al-Bukhari Book 9, Hadith 45
Allah's Messenger (ﷺ) disliked to sleep before the `Isha' prayer and to talk after it.
My companions, who came with me in the boat and I landed at a place called Baqi . The Prophet (ﷺ) was in Medina at that time. One of us used to go to the Prophet (ﷺ) by turns every night at the time of the `Isha prayer. Once I along with my companions went to the Prophet (ﷺ) and he was busy in some of his affairs, so the `Isha' prayer was delayed to the middle of the night He then came out and led the people (in prayer). After finishing from the prayer, he addressed the people present there saying, "Be patient! Don't go away. Have the glad tiding. It is from the blessing of Allah upon you that none amongst mankind has prayed at this time save you." Or said, "None except you has prayed at this time." Abu Musa added, 'So we returned happily after what we heard from Allah's Messenger (ﷺ) ."
`Aisha said, "Once Allah's Messenger (ﷺ) delayed the `Isha' prayer till `Umar reminded him by saying, "The prayer!" The women and children have slept. Then the Prophet (ﷺ) came out and said, 'None amongst the dwellers of the earth has been waiting for it (the prayer) except you." `Urwa said, "Nowhere except in Medina the prayer used to be offered (in those days)." He further said, "The Prophet (ﷺ) used to offer the `Isha' prayer in the period between the disappearance of the twilight and the end of the first third of the night."