"Indeed We presented the Trust to the heavens and the earth and the mountains, but they refused to undertake it and were apprehensive of it; but man undertook it. Indeed he is most unjust and ignorant." Qur'an 33:72
The meaning of this verse is not accurately translated by by many of non Arabic translators. Amaanah in Arabic is not always Trust but it has other meanings as well including The Responsibility, The obligatory, The Liability etc.
The meaning of Amaanah in this verse has been mentioned in many Hadeeths from Ahlul Bayt (AS) as The responsibility to follow the orders of Allah and His Messenger and his successors 'Ahlul Bayt' which is result of having perfect 'Aql (intellect) which is only with the human beings. That is why the heavens and the earth and the mountains could not carry it because they are unable to carry it and they were apprehensive of it. They did not refuse it in a sinful refusal like the refusal of Satan to prostrate to Adam, but they were unable to carry because they did not have the intellect to fulfill its responsibilities.