This can be stated in active form. Alternate translation: "the house of David heard the report" or "someone reported to the house of David" (See: [[rc://en/ta/man/translate/figs-activepassive]])
The word "house" is a metonym for the family living in the house. Alternate translation: "King Ahaz and his counselors" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Here "Aram" and "Ephraim" refer to their kings. Here "Ephraim" represents the whole northern kingdom of Israel. Alternate translation: "that Rezin, the king of Aram was helping Pekah, the king of Israel" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-synecdoche]])
The trembling of their hearts at this news is compared to the way trees shake when the wind blows through them. Alternate translation: "Ahaz and his people were very afraid" (See: [[rc://en/ta/man/translate/figs-simile]])