Kizami zuki or jabbing punch is a a karate move using the front arm. Several versions to practice -
1. From zenkutsu dachi (front stance), punch with the front arm, leave the punch out, making sure you have a strong hikite.
2. From zenkutsu dachi (front stance), punch with the front arm, snap the punch back, making sure you have a strong hikite, which also snaps back strongly to jyu kamae.
3. From jyu kamae or fighting stance, keep your guard up and punch with the lead arm, similar to a boxers jab, with no hikite.