Is it stipulated in the four madhhabs that premeditated murder requires a specific instrument, and what is the preponderant opinion?

The jurists differed on the definition of intentional killing. The Malikis, Shafi'is, Hanbalis, and Abu Yusuf and Muhammad from the Hanafis, held that it is striking with a sharp object or a non-sharp object. A sharp object is one that cuts and penetrates the body, such as a sword or a knife. A non-sharp object is one that is highly likely to cause death when used, such as a large stone or a large piece of wood.

Abu Hanifa held that intentional killing is: deliberately striking the victim in any part of their body with an instrument that separates parts, such as a sword or fire, because intent is an act of the heart, and it is only known through its evidence, which is the direct use of an instrument that usually causes death. This is in contrast to a heavy object, as killing with it is not considered intentional according to him.

The correct view is the first one; and its proof is what Anas (may Allah be pleased with him) narrated, that a young girl was found with her head crushed between two stones, and the Jew confessed to being the perpetrator. So, the Prophet (peace be upon him) commanded that his head be crushed between two stones.