Albert Barnes Commentary Acts 22:5

"As also the high priest doth bear me witness, and all the estate of the elders: from whom also I received letters unto the brethren, and journeyed to Damascus to bring them also that were there unto Jerusalem in bonds to be punished." — Acts 22:5 (ASV)

As also the High Priest, etc.

All the estate of the elders. Greek, All the presbytery; that is, the whole body of the sanhedrim, or great council of the nation.

Unto the brethren. The Jewish brethren, who were at Damascus. Paul here speaks as a Jew, and regards his countrymen as his brethren.