Good morning! Jesus prayed before His arrest and crucifixion as was His custom. He gave an example of a true relationship with God and caring for His disciples. They were not just His followers, but His friends whom He cared deeply for.
He wanted the best for them despite their flaws and knowing they would desert Him in His darkest hour. He still prayed for them to be holy and sanctified by the truth. God's Word is absolute truth.
Jesus lived by the Word and was the Word. He wanted His followers to live by the Word. To sanctify means to separate from profane things and dedicate to God in consecration and dedication; to purify inside and out.
Jesus prayed we would be purified and set apart to be used of God and belong to Him through the Word of truth. Live in the truth of God's Word and make a great day!