Adam Clarke on Colossians 2:17

Which are a shadow - All these things were types, and must continue in force till the Christ, whom they represented, came; the apostle therefore says that the body - the substance or design of them was of Christ - pointed him out, and the excellent blessings which he has procured. The word σκια, shadow, is often used to express any thing imperfect or unsubstantial; while the term σωμα, body, was used in the opposite sense, and expressed any thing substantial, solid, and firm. The law was but the shadow or representation of good things to come; none should rest in it; all that it pointed out is to be sought and obtained in Christ.