Does a practice that occurred during sleep without touching the vulva with the hand, but with the sensation of the tremor that results from masturbation, constitute masturbation, and is ignorance excusable in this case?

Sincere repentance expiates sin. What is forbidden regarding sexual pleasure is enjoyment outside the bounds of marriage and lawful possession (milk al-yamin). Therefore, whoever seeks pleasure in other than these ways is mistaken and transgressing. Ignorance of this lifts thein.