39 Preface الحَمدُ لِلَّهِ الَّذي وَهَبَ لي عَلَى الكِبَرِ إِسماعيلَ وَإِسحاقَ ۚ إِنَّ رَبّي لَسَميعُ الدُّعاءِYusuf Ali“Praise be to God, Who hath granted unto me in old age Isma?il and Isaac: for truly my Lord is He, the Hearer of Prayer!1Abraham was 100 years old when Isaac was born (Gen. 21:5); and as Isma'il was 13 years old when Abraham was 99, (Gen. 17:24-25), Isma'il was also a son of his father’s old age, having been born when Abraham was 86 years old. The younger son’s progeny developed the Faith of Israel and that of Christ; the elder son’s progeny perfected the more universal Faith of Islam, the Faith of Abraham the True.