Adam Clarke on Psalms 31:20

Thou shalt hide them in the secret of thy presence - בסתר פניך besether paneycha, "With the covering of thy countenance." Their life shall be so hidden with Christ in God, that their enemies shall not be able to find them out. To such a hiding-place Satan himself dare not approach. There the pride of man cannot come.

Thou shalt keep them secretly in a pavilion - Thou shalt put them in the innermost part of thy tent. This implies that they shall have much communion and union with God; that they shall be transformed into his likeness, and have his highest approbation.