John Gill Commentary Psalms 100:4

"Enter into his gates with thanksgiving, And into his courts with praise: Give thanks unto him, and bless his name." — Psalms 100:4 (ASV)

Enter into his gates with thanksgiving
The same with the gates of Zion, loved by the Lord more than all the dwellings of Jacob; the gates of Jerusalem, within which the feet of the saints stand with pleasure; the gates of Wisdom, or Christ, where his followers watch and wait; the gates into his house, the church, and the public ordinances of it.

These gates are to be entered into with thankfulness for all mercies, temporal and spiritual; for the Gospel, and Gospel opportunities and ordinances:

and into his courts with praise ;
with the sacrifice of praise, as in (Psalms 96:8) , of these courts, see (Psalms 65:4) (84:2) ,

be thankful unto him ;
for all blessings of grace in him and by him; for all things, and at all times:

and bless his name ;
by ascribing honour, blessing, and glory to him, saying, "blessed be his glorious name for ever", (Psalms 72:19) (103:1) .