He who is enthroned in heaven laughs; my Master mocks them.
MIDRASH TEHILLIM
1.....(2.6) ...enthroned in heaven laughs...
...another reading - He will make the heathen laugh in derision in one another ...
RADAK
1. He that sitteth in the heavens...
Every expression of sitting, when it is used of God has a meaning of abiding, [enduring]
Rabbi HIRSCH
1. enthroned in heaven laughs...
God, as "yosheyv bashomayim", holds in His hands the reins of all that exists and all that is yet to be on earth.
2. the Lord mocks at them
As ADONOY (actually “my Master”), He has informed the nations, through Israel and its spokesman, David, that homage to the Divine moral law is the sole path to salvation. He mocks at all attempts to expunge it from the minds of men.
RADAK
1. He Who raises up my head
so that I shall not be put to shame nor my countenance fall before my enemies, but I shall walk erect and with uplifted head; for when Thou deliverest me they will recognise and know that Thou hast pardoned me the iniquity through this punishment with which Thou dost punish me.