Why did he say "gird your loins"?
Radak: Go quickly!
What is the meaning of "do not bless him"?
Rashi: Do not greet him.
Why did he tell him not to talk to anyone?
Rashi: If he will talk much with someone, the other will ask where he is going, and he will say to revive a Mes. It is not honorable that one through whom a miracle is done, he boasts about it.
Radak: (a) He should not delay on the way (to talk). (b) His intent should be for his mission; he should not divert his mind to other matters, not in action or speech.
Malbim: Speaking with someone would interrupt the power that Elisha put in him to be in place of Elisha and perform like him 1 .
Michtav me'Eliyahu (5, p. 446): Nevu'ah and miracles depends on vision (understanding) of the heart. Gechazi was not at the level himself, only via Emunas Chachamim; he trusted his Rebbi. Through this he could revive the dead, but only as Elisha's Shali'ach. Any Hesech Da'as (diversion of the mind), even to answer Shalom, would nullify the clarity of his vision.
