First, we would like to stress that prayer is one of the most important obligations of Islam, being one of the five pillars of Islam. A Muslim should not miss any prayer; and all prayers should be performed in their appointed times to the best of one’s ability. Allah says in the Qur’an: “Indeed the prayers are enjoined on Believers at stated times.” (An-Nisa’ 4: 103)
Sheikh `Abdel Khaliq Hasan Ash-Shareef, a prominent Muslim scholar and Da`iyah, states the following:
“One is permitted to combine Zuhr and `Asr at the time of Zuhr provided that are really forced to do so and under the condition that you don’t make this a regular habit. This is based on the fact that the Prophet, peace and blessings be upon him, combined Prayers without traveling and without rain.
While saying this, however, I must stress that we are only allowed to combine zuhr and `asr by praying them both at the time of zuhr or `asr, and maghrib and `isha’ by praying them both at the time of maghrib and `isha’. We are not allowed to combine `isha’ with fajr or fajr with zuhr.”