Charles Ellicott Commentary Proverbs 22:18

"For it is a pleasant thing if thou keep them within thee, If they be established together upon thy lips." — Proverbs 22:18 (ASV)

They shall withal be fitted in your lips.— Rather, if they are established (dwell constantly) upon your lips. They are to be as a watch, and keep the door of his lips against sin (Psalms 141:3), to teach him what to say in difficulty (Mark 13:11), how to speak without fear even before kings (Psalms 119:46); by them the praises of God will ever be in his mouth (Psalms 149:6).