The term is used hundreds of times in WT literature and is a regular part of a JWs language. Here's one recent example from a GB member:
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*** w12 8/15 p. 18 A Meeting Marked by Unity and Thrilling Plans ***
Brother Herd referred to Psalm 92:12-14 and asked, “How does Jehovah enable us to flourish?” He answered: “In the spiritual paradise, God keeps us warm, protects us, and gives us refreshing waters of truth. Let us thank him for that.”
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This is one of the many subjects you won't see mentioned on JW Org. It is on WT Library cd rom