The consonants mlk pointed in the Hebrew Bible with the vowels for bošæt “shame.” Lev 18:21 forbids the sacrifice of children by fire to Molek. 2 Kings 16:3 and 21:6 mentions the kings Ahaz and Manasseh as being influenced by Assyrians and worshipping Molek at the hill of Topeth outside Jerusalem. Josiah’s reform ended this (2Kgs 23:10). Sometimes Molek is mentioned in connection with Baal etc.

It is debated whether mlk refers to an actual deity, or to the act of sacrificing itself (it often appears as lmlk in the Hebrew Bible). There is also some debate as to whether actual sacrifice did take place in some religions of the Ancient Near East, and whether the actual sacrificing of children is meant in the Hebrew Bible. It may be that it is merely a “purification of fire” which is meant. John Day argues that mlk was a term for sacrifice in Punic rituals. 

Some archeological excavations may point to the sacrifice of animals and humans (i.e. a temple in Amman 1400-1250 BCE), but on the other hand it may simply be that human bones were burnt.