" A reed swayed by the wind " (Matt.11:7)

As regards Christ's mention of a "reed swayed by the wind" (Matt.11:7), it helps us to remember that a reed in the time of Jesus was used as a pen. We see this symbol applied at Rev.11:1. There the apostle John who was the WRITER of Revelation, was given a *reed "like a rod, to measure" the temple, the altar, and those worshiping there.

When we perceive this reed that John was handed, symbolized his being assigned to create a written message (Rev.1:11,19; 14:13; 19:9; 21:5) (Rev.2:1,8,12,18; 3:1,7,14), 

and his writing was used as a rod of discipline 

(Prov.22:15;  2Sam.7:14; Luke 21:24; Matt.5:13), 

then we are able to grasp more fully why his writings "measured" God's worshipers (Rev.11:1; 22:19 b). 

The scroll of Revelation (penned by John) consists of 

God's appraisal of His people (measurement/judgment), and 

Christ's discipline to the congregations (as read in chapters 1-3).

There we find Christ's warnings to the wayward, and Christ's accounting with his final remnant of anointed servants 

(Matt.25:19;  2Cor.5:10;  Rev.20:12; John 12:48). 

As John continues to write the 22 chapters, we are given symbolic depictions of how the unfaithful are measured 

(Isa.28:17,18,19,20; Dan.5:25,26,27), and why they receive their condemnation (LINK). 

The wicked deeds they are performing are exposed, as is God's judgment upon them. 

We also receive depictions and measurements of God's temple (1Pet.2:5,9;  1Cor.3:16;  Rev.11:2; 13:4,7)

 and the altar of sacrifice (Rev.2:20; 13:8) (Rev.11:1) 

(Rev.18:5; Jer.44:21,22,23; Rev.17:1,16; 18:7,8,14,20,21,24; Matt.23:35,36; Rev.11:7,8)(Rev.13:15)<(LINK).

Since John was inspired by holy spirit in writing Revelation, his "reed"/pen was guided by that spirit. 

The spirit is symbolized by wind/breath (John 3:8; 20:22).

Therefore, "a reed swayed by the wind" is such a prophet (2Pet.1:21;  2Tim.3:16).

There have been many such reeds (Matt.2:5; 26:56; Mark 1:2; Luke 3:4; 18:31; 4:17; John 1:45; 6:45; Acts 15:15; etc.)