His saying: "He will give you two portions of His mercy," meaning: two rewards. "And He will provide you with light by which you may walk," meaning: faith with which you may be guided.
قَوْله: ﴿يُؤْتِكُمْ كِفْلَيْنِ مِنْ رَحْمَتِهِ﴾ يَعْنِي: أَجْرين ﴿وَيَجْعَلْ لَكُمْ نُورًا تمشون بِهِ﴾ يَعْنِي: إِيمَانًا تهتدون بِهِ