# They have sown wheat but harvest thornbushes

"They have sown wheat, but there is nothing to harvest but thornbushes"

# They have

"My people have"

# thornbushes

a large plant that is covered in sharp points

# exhausted

unable to do more, without any more strength

# So be ashamed of your gain because of Yahweh's anger

"So be ashamed of your tiny harvest because Yahweh is angry with you." Here the word "gain" does not mean a large amount of something, but refers to a small amount.