2 Thessalonians 2:13

But we are bound to give thanks to God always for you, brethren beloved by the Lord, because God chose you from the beginning to be saved, through sanctification by the Spirit and belief in the truth.

Titus 1:2

in the hope of eternal life, which God, who cannot lie, promised long ages ago,

Hebrews 6:13

For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself,

Hebrews 6:17

So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he interposed with an oath,

Treasury of Scripture Knowledge

Summary

Once have I sworn by my holiness that I will not lie unto David.

That i will not lie

Bible References

Once

Hebrews 6:13
For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself,

That i will not lie

2 Thessalonians 2:13
But we are bound to give thanks to God always for you, brethren beloved by the Lord, because God chose you from the beginning to be saved, through sanctification by the Spirit and belief in the truth.
Titus 1:2
in the hope of eternal life, which God, who cannot lie, promised long ages ago,