Is a man's penetration from behind full clothing—with the woman wearing underwear—considered adultery that necessitates the prescribed punishment (hadd)?

The [act of] Zina (unlawful sexual intercourse) that necessitates the prescribed punishment (حد) is the insertion of the penis into the vagina, whether it is bare or with some clothing. If the insertion occurs with a barrier of clothing, it is still considered Zina, but scholars differed regarding the necessity of ritual ablution (ghusl) in this case. In both situations, it is obligatory to repent to Allah Almighty and Glorious, and to conceal oneself. A sound repentance involves abandoning the sin, regretting having committed it, and resolving never to return to it, and it erases what came before it.