"The heavens almost break from above them," meaning: they almost split "from above them," which means: out of fear of Him who is above them. It has reached me that Ibn Abbas used to recite it as, "They split from above them."
"And they ask forgiveness for those on the earth," meaning: for the believers.
﴿يَكَادُ السَّمَاوَاتُ يَتَفَطَّرْنَ﴾ أَي: يتشققن ﴿من فوقهن﴾ يَعْنِي: من مَخَافَة من فوقهن , وَبَلغنِي أَن ابْن عَبَّاس كَانَ يقْرؤهَا ﴿ينْفَطِرْنَ من فوقهن﴾.
﴿وَيَسْتَغْفِرُونَ لمن فِي الأَرْض﴾ أَي: من الْمُؤمنِينَ.