"Complete the first row, then the one behind it, and if any row is to be left incomplete let it be the last row."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ أَتِمُّوا الصَّفَّ الأَوَّلَ ثُمَّ الَّذِي يَلِيهِ وَإِنْ كَانَ نَقْصٌ فَلْيَكُنْ فِي الصَّفِّ الْمُؤَخَّرِ