Read all Ahadith in the book of prayer - travellers by sahih al muslim

A'isha, the wife of the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ), reported: The prayer was prescribed as two rak'ahs, two rak'ahs both in journey and at the place of residence. The prayer while travelling remained as it was (originally prescribed), but an addition was made in the prayer (observed) at the place of residence.

A'isha, the wife of the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ), said Allah prescribed the prayer as two rak'ahs, then it was completed (to four rak'ahs) at the place of residence, but was retained in the same position in journey as it was first made obligatory.

A'isha reported: The prayer was prescribed as consisting of two rak'ahs, the prayer in travelling remained the same, but the prayer at the place of residence was completed. (Zuhri said he asked 'Urwa why 'A'isha said prayer in the complete form during journey, and he replied that she interpreted the matter herself as 'Uthman did.)

Yahya b. Umayya said: I told 'Umar b. al-Khattab that Allah had said: You may shorten the prayer only if you fear that those who are unbelievers may afflict you (Qur'an, iv. 101), whereas the people are now safe. He replied: I wondered about it in the same way as you wonder about it, so I asked the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) about it and he said: It is an act of charity which Allah has done to you, so accept His charity.

Ya'la b. Umayya reported: I said to 'Umar b. al-Khattab, and the rest of the hadlth is the same.

Ibn 'Abbas reported: Allah has prescribed the prayer through the word of your Prophet ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) as four rak'ahs when resident, two when travelling, and one when danger is present.

Ibn 'Abbas reported: Allah has prescribed the prayer by the tongue of your Apostle ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) as two rak'ahs for the traveller, four for the resident, and one in danger.

Musa b. Salama Hudhali said: I asked Ibn 'Abbas: How should I say prayer when I am in Mecca, and when I do not pray along with the Imam? He said: Two rak'ahs (of prayer) is the Sunnah of Abu'l-Qasim ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ).

A hadith like this has been narrated by Abu Qatada with the same chain of transmitters.

Hafs b. 'Asim said: I accompanied Ibn 'Umar on the road to Mecca and he led us in two rak'ahs at the noon prayer, then he went forward and we too went along with him to a place where he alighted, and he sat and we sat along with him, and he cast a glance to the side where he said prayer and he saw people standing and asked: What are they doing? I said: They are engaged in glorifying Allah, offering Sunnah prayer. He said: If I had done so I would have perfected my prayer; O my nephew! I accompanied the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) on a journey, and he made no addittion to two rak'ahs, till Allah called him. I accompanied Abu Bakr and he made no addition to two rak'ahs till Allah caused him to die. I accompanied 'Umar and he made no addition to two rak'ahs till Allah caused him to die. I accompanied 'Uthman and he made no addition to two rak'ahs, till Allah caused him to die, and Allah has said: There is a model pattern for you in the Messenger of Allah (al-Qur'an, xxxiii. 21).