"In Christ's name our petitions ascend to the Father. He intercedes in our behalf, and the Father lays open all the treasures of His grace for our appropriation, for us to enjoy and impart to others. “Ask in My name,” Christ says. “I do not say that I will pray the Father for you; for the Father Himself loveth you. Make use of My name. This will give your prayers efficiency, and the Father will give you the riches of His grace. Wherefore ask, and ye shall receive, that your joy may be full.” 8T 178.1"
"Hitherto have ye asked nothing in my name: ask, and ye shall receive, that your joy may be full."
The EGW passage directly quotes John 16:24 and connects it to the idea of asking in Christ's name and receiving joy.