1Sam 16:5

“10. Those who direct their intention toward heavenly things go with the doctors to offer sacrifice. And the prophet sacrifices before those who go, when the doctor binds in the hearts of those present through love what he proclaims by word. But that we may attend a little to the historical sense, we must carefully examine what is said: "Sanctify yourselves and come with me." For if they do not dare to be present at the sacrifice unless sanctified, what must we think of those who sacrifice? For to sanctify is to purify. How pure, then, ought the priests to be, where the people invited to the sacrifice are not to be admitted unless sanctified? For the sanctification of the body is chastity, and the sanctification of the mind is charity and humility. Let the one invited to the sacrifice therefore be sanctified, but he who invites is all the more compelled to be so. Let the priests note what they say to those invited: "Come with me." For the sanctified come with them if pure priests approach the service of God together with pure people. For to go with them is for the pure to approach together with the pure. For if the people are pure but the priests are not pure, they do not come with them, because they do not approach in an equal order of purity. Let such ones hear what another prophet admonishes, saying: "Be clean, you who bear the vessels of the Lord" (Isaiah 52:11). Let them likewise hear what he says: "Wash yourselves, be clean" (Isaiah 1:16). Because therefore the people must be cleansed, he says: "Sanctify yourselves." Because likewise men of the highest rank must always remain in the continual state of their purity and draw others to the pattern of their purity, he adds: "And come with me." But because the elders are invited to the sacrifice, what do they demonstrate by this type, except that for choosing a bishop, or for anointing and consecrating him, many wise and religious men must be called? Who are indeed sanctified and come, if they resolve not to follow anything carnal in that election. For them to be sanctified is to bring a spiritual and holy intention to the bestowing of the gifts of the Holy Spirit. And well is it said in the type of the chosen, both of Jesse and of his sons...”

“27. What is it for a priest to sacrifice, except to join the hearts of the elect to our Redeemer through love? As if he were saying: You wish to know whether he has come, but it does not profit to be known unless it profits to be loved. I have come therefore to sacrifice to the Lord. Hence it is that Paul expels those in whom he could not sacrifice, saying: "If anyone does not love the Lord Jesus, let him be anathema" (1 Cor. 16:22). But to those invited to the sacrifice it is said: "Sanctify yourselves, and come." The Jews therefore cannot come with us to the sacrifice of faith, because they refuse to judge the Lord Jesus from the Scriptures, but out of hatred alone they flee from hearing his preaching. Whence the Lord complains through himself, saying: "If I had not done among them the works that no one else did, they would have no sin; but now they have no excuse, because they have seen and hated both me and my Father" (John 15:24). What then is the meaning of what is said: "Sanctify yourselves, and come"? But for hearers to be sanctified is to prepare the secret place of a pure mind for hearing. For them to be sanctified is indeed to cast hatred from the heart, and to prepare purity of intention for hearing the word of preaching. Therefore the sanctified are commanded to come, because coming profits nothing for those who do not have purity of intention in hearing. And because the Holy Spirit speaks through holy teachers, he says: "Come with me" — as if to say: Attend to the one speaking in such a way that you believe the one hearing is with you, because I speak in such a way that I hear, since I myself am the one who speaks and governs the speaking. And because at the beginning of the nascent Church many of the Jews both heard devoutly and believed faithfully, it is rightly said that Jesse and his sons were sanctified by Samuel and invited to the sacrifice.”