"And do not kill your children," meaning: the infant girls buried alive, "for fear of poverty," meaning: destitution. "Indeed, their killing is a great" sin, "great."
﴿وَلَا تقتلُوا أَوْلَادكُم﴾ يَعْنِي: الموءودة ﴿خشيَة إملاق﴾ يَعْنِي: الْفَاقَةَ ﴿إِنَّ قَتْلَهُمْ كَانَ خطأ﴾ ذَنبا ﴿كَبِيرا﴾.