# If they are prophets, and if the word of Yahweh has truly come to them, let them beg Yahweh

Yahweh challenges them to beg of him. But he knows that they are not true prophets and they will not beg of him.

# if the word of Yahweh has truly come to them

"if Yahweh has truly given them messages"

# the word of Yahweh ... beg Yahweh of hosts not

"my word ... be me, Yahweh of hosts, not". Yahweh is speaking of himself in third person. 

# the house of the king of Judah

"the palace of the king of Judah"