Charles H. Spurgeon on Psalms 119:133

Order my steps in thy word. This is one of the Lord's customary mercies to his chosen, "He keepeth the feet of his saints." By his grace he enables us to put our feet step by step in the very place which his word ordains. This prayer seeks a very choice favour, namely, that every distinct act, every step, might be arranged and governed by the will of God. This does not stop short of perfect holiness, neither will the believer's desires be satisfied with anything beneath that blessed consummation.

And let not any iniquity have dominion over me. This is the negative side of the blessing. We ask to do all that is right, and to fall under the power of nothing that is wrong. God is our sovereign, and we would have every thought in subjection to his sway. Believers have no choice, darling sins to which they would be willing to bow. They pant for perfect liberty from the power of evil, and being conscious that they cannot obtain it of themselves, they cry unto God for it.