(And We granted not to any human being immortality before you;) means, O Muhammad.
(immortality) means, in this world. On the contrary,
(Whatsoever is on it (the earth) will perish. And the Face of your Lord full of majesty and honor will remain forever.) 55:26-27.
(then if you die) means, O Muhammad,
(would they live forever) means, they hope that they will live forever after you, but that will not happen; everything will pass away. So Allah says:
(Everyone is going to taste death,)
(and We shall test you with evil and with good by way of trial. ) Meaning, "We shall test you, sometimes with difficulties and sometimes with ease, to see who will give thanks and who will be ungrateful, who will have patience and who will despair." `Ali bin Abi Talhah reported from Ibn `Abbas:
(and We shall test you) means, We will test you,
(with evil and with good by way of trial.) means, with difficulties and with times of prosperity, with health and sickness, with richness and poverty, with lawful and unlawful, obedience and sin, with guidance and misguidance.
(And to Us you will be returned.) means, and We will requite you according to your deeds.