What do the futurists here think about Isaiah 25:9

[Mellontes]

What do the futurists here think the context of Isaiah 25:9 is about?

Isaiah 25:9 - And it shall be said in that day, Lo, this is our God; we have waited for him, and he will save us: this is the LORD; we have waited for him, we will be glad and rejoice in his salvation.

I am especially interested in:

1. What day the "in that day" represents.

2. What you think the phrase "he will save us" means.

3. What you think the phrase "in his salvation" means.

I believe that what Isaiah said here is foundational to New Testament truths...