It is implied that Jesus is talking about freedom from sin, which is a metaphor for being able not to sin. Alternate translation: "if the Son msets you free, you will truly be able to refrain from sin" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/figs-metaphor]])
"Son" is an important title for Jesus, the Son of God. Jesus was speaking about himself. Alternate translation: "If I, the Son, set you free" (See: [[rc://en/ta/man/translate/guidelines-sonofgodprinciples]] and [[rc://en/ta/man/translate/figs-123person]])