The Stoics thought about death deliberately and often, not out of morbidity but because a person who has genuinely absorbed that they will die makes different decisions about the time in front of them. Fear of death, on their diagnosis, is a judgement about something that has not happened and will not be experienced.
These passages also cover the harder case: not your own death but other people's. Consolation, mourning, and the plain fact that everything and everyone here is on the way out.
50 passages
"Keep before your eyes day by day death and exile, and everything that seems terrible, but most of all death; and then you will never have any abject thought, nor will you yearn for anything beyond measure."
"I walk in Nature's way until I shall lie down and rest, breathing my last in this from which I draw my daily breath, and lying down on this from which my father drew his vital seed, my mother her blood, my nurse her milk; from which for so many years I am fed and watered day by day; which bears my footstep and my misusing it for so many purposes."
"'Look from above' at the spectacle of myriad herds, myriad rites, and manifold journeying in storm and calm; diversities of creatures who are being born, coming together, passing away."
"You, Marcia, have still a mighty sorrow abiding with you, nevertheless it already appears to have become blunted: it is obstinate and enduring, but not so acute as it was at first: and this also will be taken from you piecemeal by succeeding years."
"All things that exist will very swiftly change; either they will pass into vapour, if we presume that matter is a whole, or else they will be dispersed into their atoms."
"Nowhere, or we know not where.' For in this way you will continually see that man's life is smoke and nothingness, especially if you remind yourself that what has once changed will be no more in infinite Time."
"There comes now a part of our subject which is wont with good cause to make one sad and anxious: I mean when good men come to bad ends; when Socrates is forced to die in prison, Rutilius to live in exile, Pompeius and Cicero to offer their necks to the swords of their own followers, when the great Cato, that living image of virtue, falls upon his sword and rips up both himself and the republic, one cannot help being grieved that Fortune should bestow her gifts so unjustly: what, too, can a good man hope to obtain when he sees the best of men meeting with the worst fates."
"Lucius Bibulus, a man more remarkable for goodness than for strength of character, had both his sons murdered at the same time, and even insulted by the Egyptian soldiery, so that the agent of his bereavement was as much a subject for tears as the bereavement itself."
"What ought one to be like both in body and soul, when overtaken by death; the brevity of life; the gulf of Time hereafter and gone by; the weakness of all matter."
"For him whose sole good is what is in due season, who counts it all one to render according to right reason more acts or fewer, and to whom it is no matter whether he beholds the world a longer or a shorter time—for him even death has lost its terrors."
"Alexander the Great and his stable boy were levelled in death, for they were either taken up into the same life-giving principles of the Universe or were scattered without distinction into atoms."
"We ought to take into account not only the fact that day by day life is being spent and a smaller balance remaining, but this further point also that, should we live longer, it is at least doubtful whether the intellect will hereafter be the same, still sufficient to comprehend events and the speculation which contributes to the understanding alike of things divine and human."
"All that your eyes behold will very quickly pass away, and those who saw it passing will themselves also pass away very quickly; and he who dies in extreme age will be made equal in years with the infant who meets an untimely end."
"And in all things awaiting death, with a mind that is satisfied, counting it nothing else than a release of the elements from which each living creature is composed."
"Everything material vanishes very swiftly in the Universal Substance, every cause is very swiftly taken up into the Universal Reason, and the memorial of everything is very swiftly buried in eternity."
"Now what tends to the advantage of the Whole is ever altogether lovely and in season; therefore for each individual the cessation of his life is no evil, for it is no dishonour to him, being neither of his choosing nor without relation to the common good: rather is it good, because it is in due season for the Whole, benefiting it and itself benefited by it."
"Think constantly of the death of men of all sorts, of all sorts of pursuits and of every kind of nation, so that your thought comes down to Philistio, Phoebus, and Origanio."
"The gods, who have no part in death, are not grieved because in so long an eternity they will be obliged always and entirely to suffer so many and such worthless men; and besides they take care of them in all kinds of ways."
"How admirable is the soul which is ready and resolved, if it must this moment be released from the body, to be either extinguished or scattered or to persist."
"Think continually how many physicians have died, after often knitting their foreheads over their patients; how many astrologers after prophesying other men's deaths, as though to die were a great matter; how many philosophers after endless debate on death or survival after death; how many paladins after slaying their thousands; how many tyrants after using their power over men's lives with monstrous arrogance, as if themselves immortal; how many entire cities have, if I may use the term, died, Helice, Pompeii, Herculaneum, and others innumerable."
"Dwell upon everything that exists and reflect that it is already in process of dissolution and coming into being by change and a kind of decay or dispersion, or in what way it is born to die, in a manner of speaking."
"I will not invite you to practise the sterner kind of maxims, nor bid you bear the lot of humanity with more than human philosophy; neither will I attempt to dry a mother's eyes on the very day of her son's burial."
"Alexander, Pompeius, and Julius Caesar, after so often utterly destroying whole towns and slaying in the field many myriads of horse and foot, themselves also one day departed from life."
"'The earth-born parts return to earth again, But what did blossom of ethereal seed Returns again to the celestial pole.' Or else this: an undoing of the interlacement of the atoms and a similar shattering of the senseless molecules."
"Now pass to the ages of your life, boyhood for instance, youth, manhood, old age; for each change of these was a death; was it anything to be afraid of?"
"Let us, then, refrain from unprofitable tears: for our grief will carry us away to join him sooner than it will bring him back to us: and if it tortures us without helping us, we ought to lay it aside as soon as possible, and restore the tone of our minds after their indulgence in that vain solace and the bitter luxury of woe: for unless reason puts an end to our tears, fortune will not do so."
Marcus dominates this topic, and his approach is almost always the same move - widen the frame until the individual death stops looking like an exception. Whole generations gone, the famous forgotten alongside the obscure, the rememberers dying too. It is meant to console by scale.
Whether that works on grief is a fair question, and Seneca's consolations are more honest about the difficulty than the argumentative passages are. The Stoic position is not that loss does not hurt but that it is not an injustice, and the distance between those two is where most readers will find the real argument.