Albert Barnes Commentary 2 Kings 8:11

"And he settled his countenance stedfastly [upon him], until he was ashamed: and the man of God wept." — 2 Kings 8:11 (ASV)

That is, And he (Elisha) settled his countenance, and set it (toward Hazael), until he (Hazael) was ashamed. Elisha fixed a long, meaningful look on Hazael until Hazael’s eyes fell before his and his cheek flushed. It would seem Elisha had detected the guilty thought in Hazael’s heart, and Hazael perceived that he had been discovered. This is why he was ashamed.