Passage
Thou also hast delivered me from the strivings of my people, thou hast kept me to be head of the heathen: a people which I knew not shall serve me.
Thou also hast delivered me from the strivings of my people, thou hast kept me to be head of the heathen: a people which I knew not shall serve me.
2 Samuel 22:42 They looked, but there was none to save; even unto the LORD, but he answered them not.
2 Samuel 22:43 Then did I beat them as small as the dust of the earth, I did stamp them as the mire of the street, and did spread them abroad.
2 Samuel 22:44 Thou also hast delivered me from the strivings of my people, thou hast kept me to be head of the heathen: a people which I knew not shall serve me.
2 Samuel 22:45 Strangers shall submit themselves unto me: as soon as they hear, they shall be obedient unto me.
2 Samuel 22:46 Strangers shall fade away, and they shall be afraid out of their close places.
The verse centers on "thou", "hast", "delivered", "strivings", "people", and "kept". It is saying that the verse draws attention to "thou" and "hast", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 43's "Then did I beat them as small..." into verse 45's "Strangers shall submit themselves unto me as...", so "thou" and "hast" belong inside that flow. In 2 Samuel context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "thou" and "hast" with trust shaped by these words, not by a vague optimism outside the passage.