Tex. Government Code § 301.023: ADMINISTERING OATHS.

(a) The following individuals may administer oaths to testifying witnesses:

(1) the president of the senate;

(2) the speaker of the house;

(3) the chairman or acting chairman of a standing or special committee; and

(4) the chairman or acting chairman of a joint committee.

(b) If circumstances require, a member of either house may administer an oath to a witness testifying on a matter pending in the member's house or in a committee of that house.

Acts 1985, 69th Leg., ch. 479, Sec. 1, eff. Sept. 1, 1985.