What is the difference between the Solar Hijri and Lunar Hijri calendars, and why is the difference between them approximately 42 years?

The difference between the solar year (365.2422 days) and the lunar year (354.367 days) is 10.8752 days. This means that after 33.58 solar years, a difference equivalent to a full solar year accumulates. Consequently, the time difference between calculating the Hijrah (Prophetic Migration) using solar years and lunar years is approximately 42 years, due to this difference between the two types of years.