A.T. Robertson 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)

Coming (ελθων, second aorist active participle of ερχομα), taking (αρας, first aorist active participle of αιρω, to take up),

binding (δησας, first aorist active participle of δεω, to bind). Vivid use of three successive participles describing the dramatic action of Agabus.

Paul's girdle (την ζωνην του Παυλου). Old word from ζωννυμ, to gird. See on 12:8.

His own feet and hands (εαυτου τους ποδας κα τας χειρας). Basis for the interpretation. Old Testament prophets often employed symbolic deeds (1 Kings 22:11; James 2:2; Jeremiah 13:1–7; Ezekiel 4:1–6). Jesus interpreted the symbolism of Peter's girding himself (John 21:18).

So (ουτως). As Agabus had bound himself. Agabus was just from Jerusalem and probably knew the feeling there against Paul. At any rate the Holy Spirit revealed it to him as he claims.

Shall deliver (παραδωσουσιν). Like the words of Jesus about himself (Matthew 20:19). He was "delivered" into the hands of the Gentiles and it took five years to get out of those hands.