Now it was to Abraham that the promises were made, 'and to his offspring.' It was not said 'to his offsprings,' as if many persons were meant, but the words were 'to thy offspring,' showing that one person was meant--and that was Christ.
Our fathers disciplined us for only a short time and as seemed best to them; but God disciplines us for our true good, to enable us to share his holiness.
And consequently it was necessary that he should in all points be made like 'his Brothers,' in order that he might prove a merciful as well as a faithful High Priest in man's relations with God, for the purpose of expiating the sins of his People.