Albert Barnes Commentary Matthew 10:19-20

"But when they deliver you up, be not anxious how or what ye shall speak: for it shall be given you in that hour what ye shall speak. For it is not ye that speak, but the Spirit of your Father that speaketh in you." — Matthew 10:19-20 (ASV)

Take no thought. That is, do not be anxious, or excessively concerned. (See Barnes on Matthew 6:26).

God would inspire them. This was a full promise that they should be inspired, and was a most timely consolation. Poor, and ignorant, and obscure fishermen would naturally be anxious about what they should say before the great men of the earth. People in Eastern cultures regarded kings as raised far above common mortals: as approaching divinity. How consoling, then, the assurance that God would aid them, and speak within them!