Albert Barnes Commentary Acts 21:11

"And coming to us, and taking Paul`s girdle, he bound his own feet and hands, and said, Thus saith the Holy Spirit, So shall the Jews at Jerusalem bind the man that owneth this girdle, and shall deliver him into the hands of the Gentiles." — Acts 21:11 (ASV)

He took Paul's girdle. The loose, flowing robes, or outer garments, worn in eastern countries were bound by a girdle, or sash, around the body when people ran, worked, or walked. Such a girdle was, therefore, an indispensable part of dress.

And bound his own hands and feet. This was emblematic of what would be done by the Jews to Paul. It was common for prophets to perform actions that were emblematic of the events they predicted. The design was to make the prediction more forcible and impressive by representing it visually.

Thus, Jeremiah was directed to bury his girdle by the Euphrates to denote the approaching captivity of the Jews (Jeremiah 13:4). Thus, he was directed to make bands and yokes and to put them around his neck as a sign to Edom and Moab, etc. (Jeremiah 27:2–3). Thus, the act of the potter was emblematic of the destruction that was coming upon the nation of the Jews (Jeremiah 18:4). So Isaiah walked naked and barefoot as a sign of the captivity of Egypt and Ethiopia (Isaiah 20:3–4; Compare to Ezekiel 4, Ezekiel 12, etc.).

So shall the Jews, etc. This was fulfilled. See Acts 21:33 and Acts 24.

Into the hands of the Gentiles. To be tried; for the Romans then had jurisdiction over Judea.

Note the terms "Ghost" and "Spirit" in relation to prophetic utterance. For the specific prediction so shall the Jews, see Acts 21:33 and Acts 20:23.