"Those to whom We gave the Scripture know him as they know their own sons." Al-Kalbi said: When the Messenger of Allah ﷺ arrived in Medina, Ibn al-Khattab said to Abdullah ibn Salam, "Indeed, Allah the Exalted has revealed to His Prophet that the People of the Scripture 'know him as they know their own sons.' How is this knowledge, O Ibn Salam?" He replied, "We recognize the Prophet of Allah by the description that Allah has attributed to him when we see him among you, just as one of us knows his son when he sees him among the boys. By Him whom Abdullah ibn Salam swears by, I am more certain in my knowledge of Muhammad than I am of my own son." Umar said to him, "How is that?" He said, "I have recognized him by what Allah described to us in His Book, whereas regarding my son, I do not know what his mother might have brought about." Umar said to him, "May Allah grant you success; you have hit the mark and spoken the truth."
﴿الَّذِينَ آتَيْنَاهُمُ الْكِتَابَ يَعْرِفُونَهُ كَمَا يعْرفُونَ أَبْنَاءَهُم﴾ قَالَ الْكَلْبِيّ: لما قدم رَسُول اللَّهِ ﷺ الْمَدِينَة، قَالَ ابْن الخَطَّاب لعبد اللَّه بْن سَلام [إِن اللَّه - تَعَالَى - أنزل على نبيه أَن أهل الْكتاب ﴿يَعْرِفُونَهُ كَمَا يَعْرِفُونَ أَبْنَاءَهُم﴾ كَيفَ هَذِه الْمعرفَة يَا ابْن سَلام قَالَ: نَعْرِف نَبِي اللَّه بالنعت الَّذِي نَعته [اللَّه بِهِ] إِذا رَأَيْنَاهُ فِيكُم كَمَا يعرف أَحَدنَا ابْنه؛ إِذا رَآهُ مَعَ [الغلمان]؛ وَالَّذِي يحلف بِهِ عَبْد اللَّه بْن سَلام لأَنا بِمُحَمد أَشد معرفَة مني لِابْني. فَقَالَ لَهُ عُمَر: وَكَيف ذَلِكَ؟ قَالَ عَرفته بِمَا نَعته اللَّه لَنَا فِي كِتَابه، وَأما ابْني [فَلَا أدرى] مَا أحدثته أمه. فَقَالَ لَهُ عُمَر: وفقك اللَّه، فقد أصبت وصدقت.
