'Fail' in the Bible

Yet I will not cut off every man of yours from My altar so that your eyes will fail from weeping and your soul grieve, and all the increase of your house will die in the prime of life.

Thus Samuel grew and the Lord was with him and let none of his words fail.

David said to Saul, “Let no man’s heart fail on account of him; your servant will go and fight with this Philistine.”