Hebrews 13:8-9
“Jesus Christ the same yesterday and today and for ever. Be not carried about with various and strange doctrines. For it is good that the heart be established with grace, not with meats, which have not profited them that have been occupied therein.”
In these words, “Jesus Christ the same yesterday and today and for ever,” “yesterday” means all the time that is past: “today,” the present: “for ever,” the endless which is to come. That is to say: You have heard of an High Priest, but not an High Priest who fails. He is always the same. As though there were some who said, 'He is not, another will come,' he says this, that He who was “yesterday and today,” is “the same also for ever.” For even now the Jews say, that another will come; and having deprived themselves of Him that is will fall into the hands of Antichrist.
“Be not carried about with various and strange doctrines.” Not “with strange doctrines” only, but neither with “various ones.”
“For it is a good thing that the heart be established with grace, not with meats which have not profited them that have been occupied therein.” Here he gently hints at those who introduce the observance of “meats.” For by Faith all things are pure. There is need then of Faith, not of “meats.”
Source: Homilies on the Epistle to the Hebrews (New Advent)