Albert Barnes Commentary Psalms 33:21

"For our heart shall rejoice in him, Because we have trusted in his holy name." — Psalms 33:21 (ASV)

For our heart shall rejoice in him - See the notes at Psalms 13:5.

Because we have trusted in his holy name - In "him," the "name" often stands for the person himself. See the notes at Psalms 20:1. The idea is:

• that the fact of our having put our trust in God is itself an occasion of joy or rejoicing;
• that the result will be joy, for we will never be disappointed.

It will always, and in all circumstances, be a source of joy to anyone that he HAS put his trust in the name of God.