1 Samuel 20:15

thou shalt not cut off thy mercy from my house for ever. When the LORD has cut off one by one the enemies of David from the face of the earth, remove even Jonathan from thy house if I fail thee and require it at the hand of David's enemies.

2 Samuel 21:7

But the king spared Mephibosheth, the son of Jonathan, the son of Saul, because of the LORD's oath that was between them, between David and Jonathan the son of Saul.

1 Samuel 24:21

Swear now therefore unto me by the LORD that thou wilt not cut off my seed after me and that thou wilt not destroy my name out of my father's house.

2 Samuel 9:1-7

And David said, Is anyone left of the house of Saul that I may show him mercy for Jonathan's sake?

Treasury of Scripture Knowledge

Summary

But also thou shalt not cut off thy kindness from my house for ever: no, not when the LORD hath cut off the enemies of David every one from the face of the earth.

General references

Bible References

Thou shalt

1 Samuel 24:21
Swear now therefore unto me by the LORD that thou wilt not cut off my seed after me and that thou wilt not destroy my name out of my father's house.
2 Samuel 9:1
And David said, Is anyone left of the house of Saul that I may show him mercy for Jonathan's sake?
2 Samuel 21:7
But the king spared Mephibosheth, the son of Jonathan, the son of Saul, because of the LORD's oath that was between them, between David and Jonathan the son of Saul.

General references

1 Samuel 23:18
And the two made a covenant before the LORD, and David abode in the woods, and Jonathan returned to his house.