"Let those who have been trained for service now take their places quickly in the Lord's work. House-to- house laborers are needed. The Lord calls for decided efforts to be put forth in places where the people know nothing of Bible truth. Singing and prayer and Bible readings are needed in the homes of the people. Now, just now, is the time to obey the commission, “Teaching them to observe all things whatsoever I have commanded you.” Matthew 28:20 . Those who do this work must have a ready knowledge of the Scriptures. “It is written” is to be their weapon of defense. God has given us light on His word, that we may give this light to our fellow men. The truth spoken by Christ will reach hearts. A “Thus saith the Lord” will fall upon the ear with power, and fruit will appear wherever honest service is done. CT 540.2"
"Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen."
Ellen White directly references Matthew 28:20 in this passage.