Abu Sa'id al-Khudri (may Allah be pleased with him) relates that Sayyiduna Zayd bin Thabit (may Allah be pleased with him) told him: Once the Messenger of Allah (peace and blessings be upon him) was in a garden belonging to Banu al-Najjar, riding his mule (peace and blessings be upon him), and we were with him (peace and blessings be upon him). He (peace and blessings be upon him) said: "Seek refuge with Allah from the punishment of the grave; seek refuge with Allah from the punishment of the Fire." We said: We seek refuge with Allah from the punishment of the grave; we seek refuge with Allah from the punishment of the Fire. He (peace and blessings be upon him) said: "Seek refuge with Allah from trials, the open and the hidden." We said: We seek refuge with Allah from trials, the open and the hidden. He (peace and blessings be upon him) said: "Seek refuge with Allah from the trial of the Dajjal." The people said: We seek refuge with Allah from the trial of the Dajjal.
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4767