"And when We saved you from the people of Pharaoh, who were afflicting you," meaning: subjecting you to "the worst of the torment," meaning: the most severe of it. "They were slaughtering your sons and letting your women live," meaning: they would not kill them. "And in that was a great trial from your Lord," meaning: when He saved you from it.
Muhammad said: The term 'bala' (trial) is used in transmission with various meanings; and here, it means a blessing.
﴿وَإِذْ نَجَّيْنَاكُمْ مِنْ آلِ فِرْعَوْنَ يسومونكم﴾ ﴿يلونكم﴾ (سوء الْعَذَاب﴾ أَي: أشده ﴿يُذَبِّحُونَ أَبْنَاءَكُمْ وَيَسْتَحْيُونَ نساءكم﴾ فَلَا يقتلونهن ﴿وَفِي ذَلِكُمْ بَلاءٌ من ربكُم عَظِيم﴾ يَعْنِي: إِذْ نجاكم مِنْهُ.
قَالَ مُحَمَّد: الْبلَاء يتَصَرَّف فِي النَّقْل على وُجُوه؛ وَهُوَ هَا هُنَا النِّعْمَة. (ل ٩)
