Musnad Abu Ya'la al-Mawsili 2:36

Muhammad ibn Bakkar narrated to us, Bishr ibn Maymun narrated to us, from Abdullah ibn Yusuf, from Abdullah ibn Umar ibn al-Khattab, from Umar ibn al-Khattab, who said: I heard the Messenger of Allah (may Allah bless him and grant him peace) while he was mentioning the people of a graveyard one day. He said: So he prayed over them and prayed over them much. He said: Then the Messenger of Allah (may Allah bless him and grant him peace) was asked about them, and he said: "The people of this graveyard are the martyrs of Ashkelon; they are ushered to Paradise just as a bride is ushered to her husband."