What Amir al-mu'minin said generally to his companions warning them about the dangers of the Day of Judgement.
May Allah have mercy on you! Provide yourselves for the journey because the call for departure has been announced. Regard your stay in the world as very short, and return (to Allah) with the best provision that is with you, because surely, in front of you lies a valley, difficult to climb, and places of stay full of fear and dangers.
You have to reach there and stay in them. And know that the eyes of death are approaching towards you. It is as though you are (already) in its talons and it has struck itself against you. Difficult affairs and distressing dangers have crushed you into it.
You should therefore cut away all the attachments of this world and assist yourselves with the provision of Allah's fear.
as-Sayyid ar-Radi says: A part of this saying has been quoted before through another narration.