Richard Bauckham, The Jewish World around the New Testament  (Grand Rapids: Baker, 2010), 211:

The NT student and scholar must use the Jewish literature in the first place to understand Judaism. Only someone who understands early Judaism for its own sake will be able to use Jewish texts appropriately and accurately in the interpretation of the NT. The famous warning issued by Samuel Sandmel against ‘parallelomania’ in NT studies has its most general application here. Someone who knows the Jewish literature only in the form of isolated texts selected for the sake of their apparent relationship to NT texts will not understand those texts in their own contexts (literary and otherwise) and so will not know whether they constitute real or only apparent parallels and, even supposing they are real parallels, will not be able to use them properly. A principle which NT students and even NT scholars rarely take to heart is that, for the sake of a balanced view of the relationship of Christianity to early Judaism, it is just as important to study Jewish texts which are least like anything in the NT as it is to study those with which the NT writings have most affinity.

• This book collects twenty-three of Bauckham’s essays that were published between 1976 and 2008. Sample PDF.
• It was originally published in 2008 by Mohr Siebeck (WUNT 233).
• The above quotation comes from “The Relevance of Extracanonical Jewish Texts to New Testament Study,” in Hearing the New Testament: Strategies for Interpretation (ed. by Joel B. Green; Grand Rapids: Eerdmans, 1995), 90–108 (2nd ed.; 2010).

Related:

1. Six helpful resources that explain the nature and significance of extracanonical Jewish literature
2. Tom Schreiner warns, “Too often in NT studies alleged background material is used to ‘prove’ various interpretations. Anyone who reads in NT studies knows how speculative such reconstructions can be. In reading such reconstructions I have often wondered why we complain about systematic theologians being speculative!”