"[That] He may forgive you of your sins" means: He will forgive you all of your sins, and "min" (of) is an expletive. "And delay you to a specified term" means: until your [appointed] time, so that your death may occur without punishment. "Indeed, the term of Allah" means: the Day of Resurrection, according to the interpretation of al-Hasan. "If you knew" means: you would have known that the Resurrection is coming.
﴿يغْفر لكم من ذنوبكم﴾ أَيْ: يَغْفِرُ لَكُمْ ذُنُوبَكُمْ كُلَّهَا و (من) صلةٌ ﴿وَيُؤَخِّرْكُمْ إِلَى أَجَلٍ مُسَمًّى﴾ إِلَى مُدَّتِكُمْ، فَيَكُونُ مَوْتُكُمْ بِغَيْرِ عَذَاب ﴿إِن أجل الله﴾ يَعْنِي: الْقِيَامَةَ؛ فِي تَفْسِيرِ الْحَسَنِ ﴿لَو كُنْتُم تعلمُونَ﴾ لعلمتم أَن الْقِيَامَة؛ جائية
