The Shamir
To build the Beis HaMikdash without iron, Shlomo needed the shamir that splits stone, and the Gemara tells how it was found.
The Beis HaMikdash was to be built without the sound of any iron tool. How, Shlomo asked the chachamim, can the stones be cut without iron? They told him of the shamir, a tiny creature that splits stone, which Moshe had used to engrave the stones of the Kohen Gadol's garments. No one knew where it was, but the Gemara tells that Ashmedai, king of the demons, might know.
Shlomo sent his faithful Benayahu ben Yehoyada with a chain and a ring engraved with Hashem's Name. Benayahu found the mountain where Ashmedai drank from a sealed pit, drained the water, and filled the pit with wine. Ashmedai came, checked his seal, and found wine. Wine is a mocker, he said, quoting Shlomo's own Mishlei, and refused to drink, but in the end thirst overcame him, and he drank and fell asleep. Benayahu bound him with the chain. When Ashmedai struggled, Benayahu warned him that the Name of his Master was upon him.
Brought before Shlomo, Ashmedai measured four cubits with a reed and threw it down. When you die, he said, this is all you will have in the world, and yet you are not satisfied until you conquer me too? I want nothing from you, Shlomo answered. I need to build the house of Hashem, and for that I need the shamir.
Ashmedai revealed that the prince of the sea had entrusted the shamir to the hoopoe bird. Shlomo's men found its nest and covered the chicks with glass; the bird brought the shamir to break through to them, the men took it, and the work of the Beis HaMikdash went forward.
Source: Gemara, Gittin 68a–b (Talmud Bavli); Melachim I 6:7; Mishlei 20:1. English: The William Davidson Talmud (Koren–Steinsaltz).
Ashmedai accused Shlomo of wanting to conquer everything. Shlomo's answer was simple: I want nothing for myself; I need this one thing to build Hashem's house. This week, when you find yourself reaching for more, a purchase, a promotion, an argument to win, stop and ask in one sentence: what do I actually need, and what is it for? If the answer is something that builds your home, your family or your avodah, pursue it fully. If not, let it go.