There are many times that fairy tales mimic or are based on pieces of the Tanakh. Whether or not they are intended to be that way is up for discussion, but I enjoy noticing it when it occurs. I realized that the true version of “The Little Mermaid” (link here) has a scene that mirrors the one with David and Saul in the cave in I Samuel 24 per some of the commentaries.
We have given our hair to the witch,” they said, “so that she would send you help, and save you from death tonight. She gave us a knife. Here it is. See the sharp blade! Before the sun rises, you must strike it into the Prince’s heart, and when his warm blood bathes your feet they will grow together and become a fish tail. Then you will be a mermaid again, able to come back to us in the sea, and live out your three hundred years before you die and turn into dead salt sea foam. Make haste! He or you must die before sunrise. Our old grandmother is so grief-stricken that her white hair is falling fast, just as ours did under the witch’s scissors. Kill the Prince and come back to us. Hurry! Hurry! See that red glow in the heavens! In a few minutes the sun will rise and you must die.” So saying, they gave a strange deep sigh and sank beneath the waves.The little mermaid parted the purple curtains of the tent and saw the beautiful bride asleep with her head on the Prince’s breast. The mermaid bent down and kissed his shapely forehead. She looked at the sky, fast reddening for the break of day. She looked at the sharp knife and again turned her eyes toward the Prince, who in his sleep murmured the name of his bride. His thoughts were all for her, and the knife blade trembled in the mermaid’s hand. But then she flung it from her, far out over the waves. Where it fell the waves were red, as if bubbles of blood seethed in the water. With eyes already glazing she looked once more at the Prince, hurled herself over the bulwarks into the sea, and felt her body dissolve in foam.
It’s the same as the David and Saul scene. David takes the knife, plans to kill Saul (per the commentator Ralbag; not every commentator thinks that David ever considered killing him) but then he cannot do it. Instead, he simply cuts off a piece of his cloak.