Aishah said, "The Prophet ﷺ prayed the Isha prayer, then he prayed eight rakahs and two rakahs while sitting, and two rakahs between the two calls to prayer, and he never abandoned them."
ﷺ قالت: صلى النبي ﷺ العشاء، ﷺ ثم صلى ثمان ركعات، وركعتين جالسا، وركعتين بين الندائين، ولم يكن يدعهما أبدا.
Bukhari narrated it in the Book of Tahajjud (1159), from Abdullah bin Yazid, who said, Saeed narrated to us, he is Ibn Abu Ayub, who said, Jafar bin Rabia narrated to me, from Arak bin Malik, from Abu Salama, from Ayesha, and she mentioned something similar.