"I have been instructed to say, in reference to the medical missionary work, that there is danger of swaying things too heavily in one line. But what I say on this point must not be understood as in any sense justifying those who have held themselves aloof from medical missionary work. There are many who have not been in sympathy with this work. They should now be very careful how they speak in regard to it, for they are not intelligent on the subject because they have not walked in the light. Whatever their position in the work of God, they should be very careful not to give utterance to sentiments that will discourage and hinder our conferences from taking hold of this work. The position that some have occupied in reference to medical missionary work makes it impossible for their words on this subject to have any weight. They are not clear-sighted; their judgment is warped. 8T 166.2"
"Wherefore, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath:"
Both passages emphasize the importance of careful speech and listening, especially when lacking full understanding. James 1:19 is a general principle, while the EGW passage applies it specifically to the medical missionary work. The connection is valid but not a direct quote or explicit allusion.
"Every branch of the work is needed, but every branch of the work is to be under the supervision of God. The medical missionary work is to be to the cause of God as the right hand to the body. It would not be right for all the strength of the body to go into the right hand, and neither would it be right for all the strength of the cause of God to be used in medical missionary work. The ministry of the word must be sustained, and there must be unity, perfect oneness, in God's work. Those who have felt no interest in medical missionary work are treating the right hand of God's cause disrespectfully. Let all such change their attitude toward this work. Let them speak as few words as possible until they stand in a right position. Silence is eloquence when the mind is not sanctified and therefore cannot discern spiritual things. 8T 166.3"
"For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ."
The EGW passage uses the analogy of the body and its members, specifically the right hand, to illustrate the importance of medical missionary work within the larger cause of God. This is a clear parallel to 1 Corinthians 12:12, which uses the same analogy to describe the unity of the church.