וַיַּגִּ֣דוּ לְשָׁא֗וּל וַיִּשְׁלַח֙ מַלְאָכִ֣ים אֲחֵרִ֔ים וַיִּֽתְנַבְּא֖וּ גַּם־הֵ֑מָּה וַיֹּ֣סֶף שָׁא֗וּל וַיִּשְׁלַח֙ מַלְאָכִ֣ים שְׁלִשִׁ֔ים וַיִּֽתְנַבְּא֖וּ גַּם־הֵֽמָּה׃
And when it was told Saul, he sent other messengers, and they also prophesied. And Saul sent messengers again the third time, and they also prophesied.
Read midrashic interpretation of I Samuel 19:21: and classical rabbinic exegesis.