Al-Hakam said: When Matar bin Najiyah gained control over Kufah, he ordered Abu Ubaydah bin Abdullah to lead the people in prayer, and he led them in prayer. When he raised his head from bowing, he would lengthen the standing. I asked Ibn Abi Layla about this, and he related the narration of Sayyiduna al-Bara' bin Azib (may Allah be pleased with him): "When the Messenger of Allah (peace and blessings be upon him) prayed, his prayer was nearly balanced. When he bowed, raised his head from bowing, prostrated, or paused between the two prostrations, the length of his pause was about equal."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2753