Sayyiduna Zayd bin Thabit (may Allah be pleased with him) was asked about the recitation in Zuhr and Asr, and he said: "The Messenger of Allah (peace and blessings be upon him) used to lengthen the recitation and would move his lips."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4896