For David, after he had served the purpose of God in his own generation, fell asleep and was buried among his fathers and experienced decay [in the grave];

So that he should live on eternally,
That he should never see the pit (grave) and undergo decay.

What man can live and not see death?
Can he rescue his soul from the [powerful] hand of Sheol (the nether world, the place of the dead)? Selah.

It had been revealed to him by the Holy Spirit that he would not die before he had seen the Lord’s Christ (the Messiah, the Anointed).

He who believes and trusts in the Son and accepts Him [as Savior] has eternal life [that is, already possesses it]; but he who does not believe the Son and chooses to reject Him, [disobeying Him and denying Him as Savior] will not see [eternal] life, but [instead] the wrath of God hangs over him continually.”

I assure you and most solemnly say to you, if anyone keeps My word [by living in accordance with My message] he will indeed never, ever see and experience death.”

By faith [that pleased God] Enoch was caught up and taken to heaven so that he would not have a glimpse of death; and he was not found because God had taken him; for even before he was taken [to heaven], he received the testimony [still on record] that he had walked with God and pleased Him.

General references

I will establish your seed forever
And I will build up your throne for all generations.” Selah.