What is the significance of "Gei Ben Hinom"?
Malbim: There they burned their children in fire (7:31).
What is "Sha'ar ha'Charsis"?
Rashi: It is ha'Ashpos (Radak - "Sha'ar ha'Ashpos" (Nechemyah 2:13); there they cast earthenware shards. Also Yonason translates 'the gate of Kilkalta (wasteheap).'
Radak: It is the gate from which people go out to Gei Ben Hinom.
Radak citing Yerushalmi Eruvin 5:1: It is a gate of the Azarah, in the east. 1 Malbim - Molech (to which they burned their children) is special to the sun [which rises in the east]. The gate was called Sha'ar ha'Shemesh.
Radak (here and Melachim II, 11:5 citing the Yerushalmi): It had seven names. It is called Sha'ar Sur, for Tamei people separated from there (they may not enter) - "Suru Tamei" (Eichah 4:15). It is called "Sha'ar ha'Yesod", for there they are Meyased (establish) the Halachah (the Sanhedrin sits there). It is called Sha'ar Charsis, for it is in line with the shining of the sun [in the morning] - "ha'Omer la'Cheres v'Lo Yizrach" (Iyov 9:7). It is called Sha'ar ha'Eisun, for it is used to enter and leave [the Azarah. Eisun is an expression of coming - "v'Asa me'Rivevos Kodesh" (Devarim 33:2). It is called Sha'ar ha'Tavech, for it is in the middle (between) two gates (of Ezras Nashim, and of the Heichal). It is called Sha'ar Chadash, for there Chachamim were Mechadesh a Halachah (that a Tevul Yom may not enter the Ezras Nashim). It is called Sha'ar Elyon, for it is l'Ma'alah (above) me'Ezras Yisrael. (Tosfos Yom Tov Midos 2:6 and others question this text, for it is not above Ezras Yisrael in Kedushah, nor in elevation. It seems that the Rambam's text (Hilchos Klei ha'Mikdash 7:6) was 'above Ezras Nashim.' - PF)
Which words will Hashem speak to Yirmeyah?
Radak: They are what I tell you now, from "v'Amarta
