en_tn/2ch/10/10.md

made their yoke heavy

A heavy yoke is a metaphor for very difficult labor and cruel treatment. This metaphor is continued in verses 10 and 11. See how you translated a similar phrase in 2 Chronicles 10:04. Alternate translation: "treated them cruelly" or "forced them to work very hard" (See: rc://en/ta/man/translate/figs-metaphor)

My little finger is thicker than my father's waist

This metaphor means that Rehoboam is more cruel and intimidating than his father. Alternate translation: "I rule much more harshly than my father ever did" or "I am much harsher than my father" (See: rc://en/ta/man/translate/figs-metaphor)