It is narrated from Hazrat Urwah bin Zubair that he heard Sayyida Aisha (may Allah be pleased with her) saying: Indeed, in the beginning, the prayer was made obligatory as two rak‘ahs, then the prayer during travel (two rak‘ahs) was kept as it was, and the prayer during residence (four rak‘ahs) was completed. So I said to Urwah: Then what is the reason that you perform the full prayer (four rak‘ahs) during travel? He replied: She used to interpret it as Sayyiduna Uthman (may Allah be pleased with him) interpreted it. The Imam narrates from his teacher Sa‘id bin Abdur Rahman Makhzumi with the same chain as the aforementioned narration, but in this, instead of «‏‏‏‏سمع، اخبرني» ‏‏‏‏, the narration is from «‏‏‏‏عن» ‏‏‏‏ in all places.

Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that Allah Almighty has, through the tongue of your Prophet (peace be upon him), made obligatory four rak‘ahs of prayer in residence, two rak‘ahs in travel, and one rak‘ah in fear.