and once To’phet (place of burning), was in the southeast extremity of the “valley of the son of Hinnom” (Jeremiah 7:31), which is “by the entry of the east gate” (Jeremiah 19:2). The locality of Hinnom is to have been elsewhere (see Hinnom). It seems also to have been part of the king’s gardens and watered by Siloam, perhaps a little to the south of the present Birket el-Hamra. The name Tophet occurs only in the Old Testament (2 Kings 23:10; Isaiah 30:33; Jeremiah 7:31-32; 19:6, 11-14). The New does not refer to it, nor does the Apocrypha. Tophet has been variously translated. The most natural meaning seems that suggested by the occurrence of the word in two consecutive verses, in one of which it is a tabret and in the other Tophet (Isaiah 30:32-33). The Hebrew words are nearly identical, and Tophet was probably the king’s “music-grove” or garden, denoting originally nothing evil or hateful. Certainly there is no proof that it took its name from the beaten to drown the cries of the burning victims that passed through the fire to Molech. Afterward it was defiled by idols and polluted by the sacrifices of Baal and the fires of Molech. Then it became the place of abomination, the very gate or pit of hell. The pious kings defiled it and threw down its altars and high places, pouring into it all the filth of the city, till it became the “abhorrence” of Jerusalem.
Smith's Bible Names Dictionary (1866)