Matthew 26:48

Gave them a sign (edwken autoi shmeion). Probably just before he reached the place, though Mark ( Mark 14:44 ) has "had given" (dedwkei) which certainly means before arrival at Gethsemane. At any rate Judas had given the leaders to understand that he would kiss (pilhsw) Jesus in order to identify him for certain. The kiss was a common mode of greeting and Judas chose that sign and actually "kissed him fervently" (katepilhsen, verse Mark 49 ), though the compound verb sometimes in the papyri has lost its intensive force. Bruce thinks that Judas was prompted by the inconsistent motives of smouldering love and cowardice. At any rate this revolting ostentatious kiss is "the most terrible instance of the ekousia pilhmata ecqrou ( Proverbs 27:6 )," the profuse kisses of an enemy (McNeile). This same compound verb occurs in Luke 7:38 of the sinful woman, in Luke 15:20 of the Father's embrace of the Prodigal Son, and in Acts 20:37 of the Ephesian elders and Paul.