to a mountain: The tribe of Issachar received much of the plain of Jezreel, also called Esdraelon. Mount Tabor was an important mountain in this area. It was likely the mountain being referred to here. Later tradition says this mountain was a place of worship (Hosea 5:1).
We do not know exactly what kind of worship took place there. However, it was probably proper worship, even though it did not happen at the temple in Jerusalem (see 1 Kings 18:30, 32).
The phrase the abundance of the sea might refer to trade and fishing. The tribe of Zebulun may have benefited from the sea when their western border reached the Mediterranean Sea( see Genesis 49:13).