How old Isaac was at the time of this sacrifice there is no means of accurately ascertaining. He was probably in the vigour of early manhood. He was able to take his share in the work of cutting wood for the burnt offering and carrying the faggots a considerable distance. It was necessary too that this sacrifice should be made on Isaac's part not with the timorous shrinking or ignorant boldness of a boy, but with the full comprehension and deliberate consent of maturer years. It is probable that Abraham was already preparing, if not to yield to Isaac the family headship, yet to introduce him to a share in the responsibilities he had so long borne alone. From the touching confidence in one another which this incident exhibits, a light is reflected on the fond intercourse of former years. Isaac was at that time of life when a son is closest to a father, mature but not independent; when all that a father can do has been done, but while as yet the son has not passed away into a life of his own. And Isaac was no ordinary son. The man of business who has encouraged and solaced himself in his toil by the hope that his son will reap the fruit of it and make his old age easy and honoured, but who outlives his son and sees the effort of his life go for nothing; the proprietor who bears an ancient name and sees his heir die--these are familiar objects of pathetic interest, and no heart is so hard as to refuse a tear of sympathy when brought into view of such heart-withering bereavements. But in Abraham all fatherly feelings had been evoked and strengthened and deepened by a quite peculiar experience. By a special and most effectual discipline he had been separated from the objects which ordinarily divide men's attention and eke out their contentment in life, and his whole hopes had been compelled to centre in his son. It was not the perpetuation of a name nor the transmission of a well-known and valuable property; it was not even the gratification of the most justifiable and tender of human affections, that was crushed and thwarted in Abraham by this command; but it was also and especially that hope which had been aroused and fostered in him by extraordinary providences and which concerned, as he believed, not himself alone but all men.