’Umar said to Sa’d: people complain against you for everything, even for prayer. He replied: I prolong the first two rak’ahs of prayer and make the last two rak’ahs brief; I do not fall short of following the prayer offered by the Messenger of Allah(May peace be upon him). He said: I think so about you.
Sunan Abi Dawud Book 2, Hadith 413