My question is about combining and shortening the prayers. What is the distance for doing so? When we start our return journey say after Asr then can we pray Isha and Magrib combining and shortening them, when we reach home? At the time of Magrib we will be in journey in the bus or train or flight, we will reach home only after Isha. Or should we pray Magrib at the right time in the vehicle? If that is so, how will we make Wudu? Hope you will answer these questions.
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
A distance that entitles one to shorten one's prayers is 83 km. So, whoever travels for 83 km for some permissible goal can shorten and combine his/her prayers (Thuhr with ‘Asr and Maghrib with ‘Isha) at the time of the first or the second prayer, whether he/she travels by land, sea or air. For example, one can shorten [four Rak’as prayer becomes two] the prayer and combine the Thuhr and ‘Asr in the time of Thuhr or in the time of ‘Asr, and we can do the same with Maghrib and ‘Isha.
As a rule, facing the Qiblah constitutes an essential condition for the validity of the prayer.
The conditions for the validity of the prayer include Qiyam (standing), Rukoo’ (bowing low), Sujood (prostration), sitting (in Tashahhud) and so on of other conditions. Neglecting any of the above-mentioned conditions invalidates the prayer unless one cannot meet same condition such as when one cannot make Sujood and so on. This ruling applies to those who are present or traveling and only in connection with the obligatory prayers.
Thus, it is impermissible to perform the obligatory prayers while on a mount (means of transport). But, if one fears losing company or some harm, then he is allowed to perform his obligatory prayers while on a mount.
Anyway, if one can combine Thuhr and ‘Asr or Maghrib and ‘Isha and perform them in the time of the first of each, before boarding a ship or plane; or delays them all and performs Thuhr and ‘Asr combined in the time of ‘Asr and Maghrib and ‘Isha combined in the time of ‘Isha. This last alternative is better provided that one has to make the intention of combination at the time of the first of each pair. Another condition is that an airport or railway station should be outside of the place of his/her living and separate from his city.
By the way, you have to know that you can perform Maghrib and ‘Isha combined at your home but not to shorten ‘Isha since your arrival at home prevents you from making use of the traveling concession.
As for your question concerning ablution, this is easy as long as you are boarding a plane or train, where there are bathrooms. Even when you are travelling by your car, you can stop to perform ablution. But if water is not available and you fear that the prescribed time of the prayer will expire, then you can make Tayammum (dry ablution). Tayammum is as follows: (1) strike your both hands slightly on pure earth/sand/stone; (2) and then, shake hands off and wipe the face and hands, right first, once.
Allah knows best.
You can search for fatwa through many choices