Muhammad ibn al-Hasan al-Saffar, from Abdullah ibn Amir, from Abd al-Rahman ibn Abi Najran, from Abdullah ibn Sinan, from Abu Abdillah عليه السلام, peace be upon him, who said: I (narrator) asked Imam عليه السلام about ‘shortening (the prayer).’ Imam عليه السلام said: “When you are in the place in which you hear the call to prayer, then complete, and when you are in the place in which you do not hear the call to prayer, then shorten. And when you arrive from a journey, then it is like that.”