Acts 23:5

“Brothers,” Paul replied, “I was not aware that he was the high priest, for it is written: ‘Do not speak evil about the ruler of your people.’”

Note Exodus 22:28 (see also LXX)

BSB · Berean Standard Bible
Then said Paul, I wist not, brethren, that he was the high priest: for it is written, Thou shalt not speak evil of the ruler of thy people.
KJV · King James Version
Paul said, “I didn’t know, brothers, that he was high priest. For it is written, ‘You shall not speak evil of a ruler of your people.’”
WEB · World English Bible
And Paul said, I knew not, brethren, that he was high priest: for it is written, Thou shalt not speak evil of a ruler of thy people.
ASV · American Standard Version

Related passages

From the Treasury of Scripture Knowledge, grouped by the word they explain.

I wist
Soon after the holding of the first council at Jerusalem, Ananias, son of Nebedenus, was deprived of the high priest's office, for certain acts of violence, and sent to Rome, whence he was afterwards released, and returned to Jerusalem. Between the death of Jonathan, who succeeded him and was murdered by Felix, and the high priesthood of Ismael, who was invested with that office by Agrippa, an interval elapsed in which this dignity was vacant. This was the precise time when Paul was apprehended; and the Sanhedrin being destitute of a president, Ananias undertook to discharge the office. It is probable that Paul was ignorant of this circumstance.
Acts 24:17
Thou
Exodus 22:28; Ecclesiastes 10:20; 2 Peter 2:10; Jude 1:8, 9