فَلَمَّا بَلَغَ مَعَهُ السَّعْيَ
And, when he (his son) was old enough to walk with him,
means, when he grew up and started to go with his father and walk with him, for Ibrahim used to go every so often to check on his son and his mother in the land of Faran (i.e., Makkah), to see how they were doing. It was said that he used to ride on Al-Buraq, traveling there swiftly, and Allah knows best.
It was reported from Ibn Abbas, peace be upon him, Mujahid, Ikrimah, Sa`id bin Jubayr, Ata' Al-Khurasani, Zayd bin Aslam and others that
فَلَمَّا بَلَغَ مَعَهُ السَّعْيَ
(And, when he (his son) was old enough to walk with him), means,
when he became a young man and was able to work as his father did.
فَلَمَّا بَلَغَ مَعَهُ السَّعْيَ قَالَ يَا بُنَيَّ إِنِّي أَرَى فِي الْمَنَامِ أَنِّي أَذْبَحُكَ فَانظُرْ مَاذَا تَرَى
And, when he (his son) was old enough to walk with him, he said;
"O my son! I have seen in a dream that I am slaughtering you. So look what you think!"
`Ubayd bin Umayr said,
"The dreams of the Prophets are revelation," then he recited this Ayah;
قَالَ يَا بُنَيَّ إِنِّي أَرَى فِي الْمَنَامِ أَنِّي أَذْبَحُكَ فَانظُرْ مَاذَا تَرَى
(he said;"O my son! I have seen in a dream that I am slaughtering you. So look what you think!").
He told his son that in order to make it easier for him, and also to test his patience and resolve, at a young age, in obeying Allah and obeying his father.
قَالَ يَا أَبَتِ افْعَلْ مَا تُوْمَرُ
He said;"O my father! Do that which you are commanded..."
meaning, `obey the command of Allah and sacrifice me.'
سَتَجِدُنِي إِن شَاء اللَّهُ مِنَ الصَّابِرِينَ
if Allah wills, you shall find me of the patient.
meaning, `I will be patient and will seek the reward for that with Allah.'
He, may peace and blessings be upon him, believed in what had been promised.
Allah said;
وَاذْكُرْ فِى الْكِتَـبِ إِسْمَـعِيلَ إِنَّهُ كَانَ صَـدِقَ الْوَعْدِ وَكَانَ رَسُولاً نَّبِيّاً
وَكَانَ يَأْمُرُ أَهْلَهُ بِالصَّـلَوةِ وَالزَّكَـوةِ وَكَانَ عِندَ رَبِّهِ مَرْضِيّاً
And mention in the Book Ismail. Verily, he was true to what he promised, and he was a Messenger, (and) a Prophet. And he used to enjoin on his family the Salah and the Zakah, and his Lord was pleased with him. (19;54-55)
فَلَمَّا أَسْلَمَا وَتَلَّهُ لِلْجَبِينِ