1 Samuel 20:15

And let not your mercy ever be cut off from my family, even when the Lord has sent destruction on all David's haters, cutting them off from the face of the earth.

2 Samuel 21:7

But the king did not give up Mephibosheth, the son of Saul's son Jonathan, because of the Lord's oath made between David and Jonathan, the son of Saul.

1 Samuel 24:21

So give me your oath by the Lord, that you will not put an end to my seed after me or let my name be cut off from my father's family.

2 Samuel 9:1-7

And David said, Is there still anyone of Saul's family living, so that I may be a friend to him, because of Jonathan?

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
So give me your oath by the Lord, that you will not put an end to my seed after me or let my name be cut off from my father's family.
2 Samuel 9:1
And David said, Is there still anyone of Saul's family living, so that I may be a friend to him, because of Jonathan?
2 Samuel 21:7
But the king did not give up Mephibosheth, the son of Saul's son Jonathan, because of the Lord's oath made between David and Jonathan, the son of Saul.

General references

1 Samuel 23:18
And the two of them made an agreement before the Lord: and David went on living in Horesh, and Jonathan went back to his house.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain