Ibn ‘Umar said:

God's Messenger used to command us to be brief, and he would recite <i>as-Saffat</i> (Al-Qur’an; 37) when he was our <i>imam</i>. Nasa’i transmitted it.

وَعَنِ ابْنِ عُمَرَ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَأْمُرُنَا بِالتَّخْفِيفِ وَيَؤُمُّنَا ب (الصافات) رَوَاهُ النَّسَائِيّ