Sahih Bukhari

Narrated Jabir bin Samura:`Umar said to Sa`d, ""The people complained against you in everything, even in prayer."" Sa`d replied, ""Really I used to prolong the first two rak`at and shorten the last two and I will never shorten the prayer in which I follow Allah's Messenger (ﷺ)."" `Umar said, ""You are telling the truth and that is what I think about you.""