What should one do who has entered into ihram for Hajj from home, then discovered that his travel time has been delayed until the evening? Should he remain in his state of ihram or wear tailored clothes, and what is the expiation for doing so if he does?

Ihram is the intention to enter into the ritual, not merely wearing the Ihram garments. Therefore, whoever did not intend to enter into Ihram is permitted to remove the Ihram clothes. As for one who did intend to enter into Ihram, it is not permissible for him to wear regular clothes before exiting the state of Ihram, because whoever enters into Ihram for Hajj or Umrah is not permitted to wear sewn garments until after exiting the state of Ihram. Exiting the state of Ihram is achieved by one of three matters: completing the ritual, or exiting if a condition was stipulated and met, or being prevented (from continuing the ritual). Whoever wears his clothes before exiting the state of Ihram without an excuse commits a sin and is obligated to offer a fidyah, which is sacrificing a sheep, or feeding six needy people, or fasting three days.