Musannaf Ibn Abi Shayba 3:1447

Waki’ narrated to us, from Ibn Abi Dhi’b, from al-Maqburi, from ‘Urwah ibn al-Zubayr, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever fills a gap in a row, Allah raises him a degree by it, or builds for him a house in Paradise by it."