Musannaf Ibn Abi Shayba 37:379

Yazid ibn Harun narrated to us, he said: Ali ibn Mas'ada informed us, from Rabah ibn Ubaydah, from Yusuf ibn Abdullah ibn Salam, he said: Abdullah ibn Salam said: The people will remain for forty years after the emergence of the Dajjal, and palm trees will be planted, and markets will be established.