What is the authenticity of the Hadith: "Two types of dead meat and two types of blood have been made lawful for us," and what is its sound interpretation? Based on this, is it permissible to eat the liver and spleen from animals not slaughtered according to the Islamic method? Is the Christian seller's confirmation regarding the mentioned method of slaughter sufficient for purchasing meat without witnessing it?

The Islamic Sharia has permitted the liver and spleen, even though they are blood, provided they come from an animal that has been ritually slaughtered. However, if they come from a carcass (maytah) or an animal killed by a blow (mawqudhah), or the like, they are forbidden due to the general prohibition of carrion as stated in the Qur'an.

The conditions for a ritual slaughter include severing the two jugular veins, the esophagus, and the windpipe. If the animal is struck on its head before slaughter, the liver and spleen are permissible to eat if the slaughter is performed while the animal has stable life (indicated by its movement and the flow of blood from it). However, if the animal dies from the blow before the slaughter, it falls under the ruling of a forbidden mawqudhah.