The psalmist writes, Psalms 103:1 (NASB)
Bless the LORD, O my soul,
And all that is within me, bless His holy name.
All three of these Psalms have as their theme to bless the Lord. After saying this, the psalmist describes the wonderful things that God has done; creation, provision for the created things, and fulfilling his promises to Abraham, Isaac and Jacob. The Lord should be blessed but what is a blessing? The word can be used as an adjective or a verb. You can say that someone is blessed or you can invoke a blessing. It seems that in these psalms, David who is attributed with Psalm 103 (Psalms 104 and 105 have no attribution) is using the word bless as a verb. He is saying that we should bless the Lord. The Lord created everything. The Lord sustains everything. The Lord fulfills his promises in ways that go beyond human understanding. Yet, the psalmists writes that we should bless the Lord. Does God need our blessing? No! He needs nothing from his creation, yet we should bless his holy name because he deserves our blessing. When Jesus taught his disciples to pray, in the first stanza, he said: Matthew 6:9 (NASB)
“Pray, then, in this way:
‘Our Father who is in heaven,
Hallowed be Your name.
Jesus agrees, that we should bless the Lord. In fact, when asked: Matthew 22:36-37 (NASB)
“Teacher, which is the great commandment in the Law?” And He said to him, “ ‘YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND.’
Jesus is teaching the universal principle that comes from these psalms, which is to bless the Lord with all that we have. Does the Lord need our blessing like a son who asks a father for his daughters hand in marriage? No, but the Lord deserves our blessing because he is holy. Therefore, I shall bless the holy name of the Lord our God (Father and Son and Holy Spirit) with all that is within me.