Theophylact of Ohrid — on 1Tim 4:7 (Commentary on 1 Timothy)

“That is, remind your own people of what I said, but do not enter into disputes with the corrupted; for it is impossible to benefit them, except perhaps in the case when a scandal might arise, as though out of our weakness we are declining to contend with them. The apostle calls the Jewish observances "fables," either because they are fabricated, or because they are untimely. For imagine if a man of about thirty years clung to the breast — how worthy of ridicule he would be for his untimeliness! He calls them "old wives' tales" because they are already outdated. Profane and unclean — because they constitute an obstacle to faith. For to subject to fear a soul that has risen above all this is characteristic of unclean rules. Train yourself in pure faith and righteous living, for in this consists godliness. Therefore, one must exercise and labor constantly; for he who trains in bodily gymnastics strives in this to the point of sweat even without any competition.”