Sayyiduna Ibn Umar (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) used to command us to keep it brief, and yet he would lead us in prayer reciting Surah al-Saffat.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5282