Boyd’s Bible Dictionary:

(recompense of God). (1) A prince of Manasseh (Num. 1:10; 2:20; 7:54; 10:23). (2) A learned president of the Sanhedrim, and Paul’s legal preceptor (Acts 5:34; 22:3).

Concise Bible Dictionary:

1. Son of Pedahzur and prince of the tribe of Manasseh (Num. 1:10; Num. 2:20; Num. 7:54,59; Num. 10:23).
2. Renowned doctor of the law, and member of the Sanhedrin, under whom Paul was educated. He gave the wise advice in the council that if the work of the apostles was of God it was useless to resist it; and if not, it would come to naught of itself. The Jews say he died a Pharisee, but ecclesiastical tradition records that he became a Christian (Acts 5:34; Acts 22:3).