It's in the Watchtower 15 November 2013, page 20, paragraph 17, point 3
You can download the PDF from the link below
https://www.jw.org/en/publications/magazines/w20131115/
Or just click the link below to go direct to the online version of the article:
https://www.jw.org/en/publications/magazines/w20131115/seven-shepherds-eight-dukes/
Watchtower 15 November 2013 (Study Edition) page 20 paragraph 17
Seven Shepherds, Eight Dukes — What They Mean for Us Today
17 Elders who are reading this article can draw some useful conclusions from the account we have just considered: (1) The most practical step that we can take to prepare for the coming attack of “the Assyrian” is that of strengthening our faith in God and helping our brothers to do the same. (2) When “the Assyrian” attacks, the elders must be absolutely convinced that Jehovah will deliver us. (3) At that time, the life-saving direction that we receive from Jehovah’s organization may not appear practical from a human standpoint. All of us must be ready to obey any instructions we may receive, whether these appear sound from a strategic or human standpoint or not. (4) Now is the time for any who may be putting their trust in secular education, material things, or human institutions to adjust their thinking. The elders must stand ready to help any who may now be wavering in their faith.