Malbim: Do not change the Navi's words to be a parable or metaphor.

Rashi #1: Even though you switch the Masa to detriment, Masa Devar Hashem is what He reveals to "Ish Devaro" and to Ish Atzaso. You switch this to an expression of Mas'oy (a burden). I did not hear so, but this is primary. ¹

Rashi #2: I heard that the Mas'oy is punishments for one who asks 'Mah Masa.'

Rashi #3: 'Masa Hashem' is an expression of Nevu'ah. The false Navi asks the true Navi to tell him Devar Hashem in the expression he heard it. The style did not explain it so well, and the false Navi switched the explanation. He spoke like [the style of] the true Navi, so people would believe him, like Chananyah ben Azur did ² . Therefore, he says 'do not ask Masa Hashem' - the style, rather, ask the true Navi what did He speak and what did He answer - the content.

Rashi #4: Hashem says His words Stam to Ish Atzaso - one who is not suspected to change it. You ask [the style] in order to reverse it, and you reversed Hashem's words, like it says "Meganvei Devarai Ish me'Es Re'ehu" (verse 30). Also this is a proper Perush.

Radak: To each man, the Masa is his word. I.e. his word alone is Masa, which implies Nevu'ah, but in his heart it is an expression of difficulty. This is "va'Hafachtem Es Divrei Elokim Chayim" - in your hearts you reverse it from Nevu'ah to difficulty.

Radak citing his father: A man's Devar is Nesi'us Sefasav (what his lips bear) - "u'Val Esa Es Shemosam Al Sefasai" (Tehilim 16:4). I.e. Nevu'ah is properly called Masa, for the Navi's mouth bears it. However, you reverse Divrei Elokim Chayim, and consider Masa a matter of difficulty.

Malbim: A man, when he speaks profane words, can speak in parables and metaphors - but how can you convert Divrei Elokim Chayim, to change them and make them a parable or metaphor?!

Radak: He is the Master of legions above and legions below. He has the ability to bring on you what He spoke.

Radak: He is our G-d, and not your G-d, for you do not believe in Him.