It's wise to save money for emergencies.

Literal

By-chance's case [for-に備えて] save-money do thing [topic-は] wise [copula-だ].

に備えて ('in preparation for,' 'to prepare for') is a set phrase — the -te form of 備える, often used to express precautionary purpose. 賢明 is a na-adjective ('wise, prudent') — typically used for deliberate judgments. The nominalized clause 貯金するのは turns the verb phrase into a topic.