וַ֠יְהִי ה֥וּא מְסַפֵּ֣ר לַמֶּלֶךְ֮ אֵ֣ת אֲשֶׁר־הֶחֱיָ֣ה אֶת־הַמֵּת֒ וְהִנֵּ֨ה הָאִשָּׁ֜ה אֲשֶׁר־הֶחֱיָ֤ה אֶת־בְּנָהּ֙ צֹעֶ֣קֶת אֶל־הַמֶּ֔לֶךְ עַל־בֵּיתָ֖הּ וְעַל־שָׂדָ֑הּ וַיֹּ֤אמֶר גֵּֽחֲזִי֙ אֲדֹנִ֣י הַמֶּ֔לֶךְ זֹ֚את הָֽאִשָּׁ֔ה וְזֶה־בְּנָ֖הּ אֲשֶׁר־הֶחֱיָ֥ה אֱלִישָֽׁע׃
And it came to pass, as he was telling the king how he had restored to life him that was dead, that, behold, the woman, whose son he had restored to life, cried to the king for her house and for her land. And Gehazi said: ‘My lord, O king, this is the woman, and this is her son, whom Elisha restored to life.’
Sha'arei Teshuvah
And also in the category of apikoros is one who calls his teacher by his name. And they said (Sanhedrin 100a) that the reason for which Gehazi was punished was because he called his teacher by his name, as it is stated (II Kings 8:5), “this is the woman and this is her son whom Elisha revived.”