"And as the Australasian Union Conference Committee studied anew, in the light of the opening providences of God, their duty to occupy new territory, they “recognized the school, the sanitarium, and the food factory as three agencies working in harmony for the education and training of home and foreign missionaries, who should go forth prepared to minister to the physical, mental, and moral needs of their fellow men.” In her report to the readers of the Review of this advance step on the part of her brethren in Australia, Mrs. White wrote: “We all feel that the work is urgent. There is no part that can wait. All must advance without delay.” LS 371.1"
"Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: 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."
Both passages discuss the importance of going out and teaching/ministering to others. Matthew 28:19-20 is the Great Commission, while the EGW passage describes the Australasian Union Conference Committee's plan to train missionaries. The connection lies in the shared emphasis on outreach and spreading a message, although the methods and specific contexts differ.