Hebrews 3:5
“And Moses verily [was] faithful in all His house, as a servant, for a testimony of those things which were to be spoken.” See also another point of superiority, that [which is derived] from the Son and the servants. You see again that by the appellation of The Son, he intimates true relationship. “But Christ as a Son over His own house.” Perceivest thou how he separates the thing made and the maker, the servant and the son? Moreover He indeed enters into His Father's property as a master, but the other as a servant.
“Whose” [i.e.] God's “house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end.” Here again he encourages them to press forward nobly, and not to fall: for we shall be the “house” of God (he says), as Moses was, “if we hold fist our confidence and our rejoicing firm unto the end.” He however (he would say) that is distressed in his trials, and who falls, does not glory: he that is ashamed, he that hides himself, has no confidence, he that is perplexed does not glory.
And then he also commends them, saying, “if we hold fast the confidence and the rejoicing of the hope firm unto the end,” implying that they had even made a beginning; but that there is need of the end, and not simply to stand, but to have their hope firm “in full assurance of faith,” without being shaken by their trials.
5. And be not astonished, that the [words] “Himself being tempted” are spoken more after the manner of men. For if the Scripture says of the Father, who was not made flesh, “The Lord looked down from heaven, and beheld all the sons of men”, that is, accurately acquainted Himself with all things; and again, “I will go down, and see whether they do altogether according to the cry of them”; and again, “God cannot endure the evil ways of men”, the divine Scripture shows forth the greatness of His wrath: much more, who even suffered in the flesh, these things are said of Christ. For since many men consider experience the most reliable means of knowledge, he wishes to show that He that has suffered knows what human nature suffers.
“Whence holy brethren” (he says “whence” instead of “for this cause”), “partakers of an heavenly calling”— (seek nothing here, if you have been called yonder— yonder is the reward, yonder the recompense. What then?) “Consider the Apostle and High Priest of our profession, Christ Jesus, who was faithful to Him that appointed Him, as also Moses [was faithful] in all His house.” (What is “who was faithful to Him that appointed Him?” it is, well disposed, protecting what belongs to Him, not allowing them to be lightly carried away, “as also Moses in all His house”) that is, know who your High Priest is, and what He is, and you will need no other consolation nor encouragement. Now he calls Him “Apostle,” on account of His having been “sent,” and “high priest of our profession,” that is of the Faith. This One also was entrusted with a people, as the other with the leadership of a people, but a greater one and upon higher grounds.
“For a testimony of those things which shall be spoken.” What do you mean? Does God receive the witness of man? Yes, certainly. For if He call to witness heaven and earth and hills (saying by the prophet, “Hear, O heaven, and give ear, O earth, for the Lord has spoken” — and “Hear ye ravines, foundations of the earth, for the Lord has a controversy with His people”), much more men; that is, that they may be witnesses, when themselves [the Jews] shameless.
Source: Homilies on the Epistle to the Hebrews (New Advent)