All my heart says ‘thank you’ to the LORD.
I will tell people about all the great things that you have done.
Psalms 9:1 NASB
I will give thanks to the LORD with all my heart;
I will tell of all Your wonders.
I will praise thee, O Lord, with my whole heart
Rather, I will give thanks.
The thanks are special for a great deliverance – a deliverance from some heathen enemy (Psalms 9:5,15), who has been signally defeated and almost exterminated (Psalms 9:5,6).
It has been conjectured that the subjugation of Ammon (2 Samuel 12:26-31) is the occasion referred to; but the expectation of further attack (Psalms 9:17-20) scarcely suits this period, when David’s wars were well-nigh over.
Perhaps the earlier victory over Ammon and Syria (2 Samuel 10:6-14), which was followed by the renewed invasion of the same nations in conjunction with “the Syrians beyond the river” (2 Samuel 10:16), is more likely to have drawn forth the composition.
I will show forth all thy marvellous works
Rather, I will tell forth, or I will recount all thy wondrous deeds.
Not necessarily miracles, but any strange and unexpected deliverances, such as the recent one (compare Psalms 40:5, 78:4).