He is trying to weasel out of testifying.
Check it out:

Rep. Darrell Issa called check in his ongoing chess match with Secretary of State John Kerry, announcing Friday that he would release the top diplomat from testifying before his committee out of concern he was trying to avoid testifying before a separate congressional panel probing the Benghazi attack.

Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, accused Kerry of obstructing congressional investigations. Issa said Kerry agreed to testify before the oversight panel on June 12 as a means to avoid testifying before the 12-member select committee investigating the Sept. 11, 2012, a1ssault on the Libyan outpost.