What is the expiation for someone who entered into a state of Ihram for Umrah from his home, but did not reach the Miqat due to missing his flight and there being no other means of transport, and then exited his state of Ihram after returning home, knowing that he forgot to say the condition (of exiting Ihram if prevented) after entering into Ihram and making the intention for Umrah?

The state of ihram for Hajj or Umrah is entered into by the mere intention. So, if a person intends to enter into ihram for Umrah, it becomes binding, and he remains in his state of ihram. He is then obligated to complete it, based on the saying of Allah the Almighty: {And complete the Hajj and Umrah for Allah}.

If he is unable to reach Mecca, then the ruling of a person prevented from continuing (muhsar) applies to him. He can then exit ihram by shaving or shortening his hair and slaughtering a sheep or a camel, which should be distributed to the poor in his place of residence.

As for the prohibitions of ihram that he committed before exiting ihram: For acts of destruction, such as cutting hair and trimming nails, he owes a fidyah (expiation) for each type of offense. This fidyah is: sacrificing a sheep in Mecca, or fasting for three days, or feeding six poor people. As for acts of indulgence, such as wearing sewn clothes and using perfume, there is no penalty if he was ignorant. If he engaged in sexual intercourse out of ignorance, his Umrah is not invalidated according to many scholars.