Rashi: Al Asher (because), like "Al Ken Tit'i Nit'ei Na'amanim", and you reversed to be "Zemoras Zar" (Yeshayah 17:10).

Rashi (From Sanhedrin 102a): Because you put Sheluchim on Malchus David (rejected them, and followed Malchei Yisrael), which made you receive Gas ? 'va'Yikach Es Gas u'Vnoseha mi'Yad Pelishtim" (Divrei ha'Yamim I, 18:1), and you despise it ? "Ya'an Ki Ma'as ha'Am ha'Zeh Es Mei ha'Shilo'ach?" (Yeshayah 8:6)? Refer to 1:14:3:1.

Radak: Because you served idolatry, and taught others to serve it, you need to send messengers to Moreshes Gas, to help you from the enemy. Moreshes Gas is a place in Eretz Pelishtim. It is mentioned in several places. David conquered it. The word Moreshes is put next to it, for David conquered it, and afterwards Pelishtim inherited it. It was an inheritance for them due to your sins ? see what sin caused to you! This was your city ? now it is in the hands of your enemies, and you must be submissive to them and send to them gifts to support you against the enemy that comes against you. Sheluchim is gifts, like "va'Yitnah Sheluchim l'Vito Eshes Shlomo" (Melachim I, 9:16). "Al Moreshes" is like El. the same applies to "va'Yelech Elkanah ha'Ramasah Al Beiso" (Shmuel I, 2:11) and similar verses.

Malbim: Gas is Meseg ha'Amah - "va'Yikach David Es Meseg ha'Amah mi'Yad Pelishtim" (Shmuel II, 8:1). Rechav'am built Morashah near Gas to be a fortified city (Divrei ha'Yamim II, 11:8). When the wall of Gas was breached, Morashah protected Gas, lest the Pelishtim take it back. When Pelishtim invaded the cities of the plain in the days of Achaz, and wanted to capture Moreshes Gas in order to take Gas, and also Pekach ben Remalyahu fought in Yehudah, Bnei Lachish compromised with him to give to him Achzav, which was by Morashah (Yehoshua 15:44), in order that they would keep Morashah, which protects Gas, lest the Pelishtim take it. Our verse teaches that you gave Shiluchim to Achzav ? refer to 1:14:3:3.

Rashi: The houses of Achziv, which was from Yehudah ¹ , and they were drawn after Pekach ben Remalyahu, in the end they will be Achzav (disappointment) to Malchei Yisrael. Pekach was killed, and was false to those who relied on him (he did not help them). This Nevu'ah was in the days of Achaz. The verse uses similar words (Achziv and l'Achzav).

Radak: Achzav is like Kezev (Sheker). The Aleph is extra. This is like "Hayo Sihyeh Li Kemo Achzav" (Yirmeyah 15:18). Batei Achziv ? they used to serve idolatry in them. Their trust in them was "Achzav Mayim Lo Ne'emanu" (ibid.) - one trusts in it to drink when he is thirsty, and he finds that it is dry. He is disappointed. "L'Malchei Yisrael" ? even though the kingdom was divided, Malchei Yehudah are Malchei Yisrael, for Yehudah is within Yisrael. Malchei Yehudah are called Malchei Yisrael ? "Kol Eleh Bnei Yehoshafat Melech Yisrael" (Divrei ha'Yamim II, 21:2), "Ki Hichni'a Hashem Es Yehudah Ba'avur Achaz Melech Yisrael" (ibid. 28:29).

Malbim: You gave Shiluchim to Achzav ? a liar, i.e. Malchei Yisrael. You gave the houses of Achziv in order to save Moreshes Gas.