Beside oneself (to be) - Vine's Expository Dictionary of New Testament Words

Beside oneself (to be)

[ 1,,G1839, existemi ]
primarily and lit. means to put out of position, displace;" hence,
(a) "to amaze," Luke 24:22 (for AV, "make ... astonished"); Acts 8:9, Acts 8:11 (AV, "bewitched"); or "to be amazed, astounded," Matthew 12:23; Mark 6:51;
(b) "to be out of one's mind, to be beside oneself," Mark 3:21; 2 Corinthians 5:13, in the latter of which it is contrasted with sophroneo, "to be of a sound mind, sober." See AMAZE.

[ 2,,G3105, mainomai ]
"to be mad, to rave," is said of one who so speaks that he appears to be out of his mind, Acts 26:24, translated "thou art beside thyself," AV; RV, "thou art mad." In Acts: Acts 26:25; John 10:20; Acts 12:15; 1 Corinthians 14:23, both versions use the verb to be mad. See MAD.

Note: For paraphroneo, 2 Corinthians 11:23, RV, See FOOL, B, No. 2.

Vine's Expository Dictionary of New Testament Words