More than one witness was required in criminal cases (Deuteronomy 17:6; 19:15). They were the first to execute the sentence on the condemned (Deuteronomy 13:9; 17:7; 1 Kings 21:13; Matthew 27:1; Acts 7:57, 58). False witnesses were liable to punishment (Deuteronomy 19:16-21). It was also an offence to refuse to bear witness (Leviticus 5:1).
Witness of the Spirit
(Romans 8:16), the consciousness of the gracious operation of the Spirit on the mind, "a certitude of the Spirit's presence and work continually asserted within us", manifested "in his comforting us, his stirring us up to prayer, his reproof of our sins, his drawing us to works of love, to bear testimony before the world," etc.