1)
What is the meaning of "uvi'Seis Matenoseichem"?
1.
Rashi: When you take the gifts that you should have given to Me, and you take them from Me to transfer your Bechoros to idolatry...
2.
Radak: This is taking and separating [a part].
2)
Why did they pass their Bechoros in fire?
1.
Malbim: The Rambam writes that the impression of Molech remained in Yechezkel's days. Women would pass the newborn over fire and coals. This is a branch of Avodas ha'Molech.
