Assalaamu alaykum. I heard a brother say that there are some differences between Quranic terminologies and Fiqh terminologies; like in Fiqh, Salaah means prayer, zakah means charity. However, sometimes in the Quran, Salah may mean praying for somebody, zakah may mean purifying. Is that right?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger. 

The Quranic terminology may correspond to the Fiqh terminology, as in the verse (which means): {And establish Salah and give Zakah} [Quran 2:43]; Allaah, with the terms Salah and Zakah here, means the two known pillars in the Fiqh terminology; so the Salah and Zakah denote their Fiqhi meaning.

We may also find what does not correspond to the Fiqh terminology in the Quranic terminology, such as the word Salah denoting supplication, and the word Zakah denoting purification; as in the verse (which means): {Take [O, Muhammad] from their wealth a charity by which you purify them and sanctify (tuzakkeehim) them with it, and invoke Allaah for them (salli 'alayhim). Indeed, your invocations are reassurance for them. And Allaah is Hearing and Knowing.} [Quran 9:103]; so here the Salah and Zakah denote the linguistic meaning [in the Arabic language].

Az-Zarkashi said in Al-Burhaan fi ‘Uloom Al-Quran:

“Every word that has two meanings is of two types:

The first type: is when one of the two meanings is more predominant than the other; so in this case, we interpret the word according to its more predominant meaning, unless there is evidence that what is meant is the less predominant meaning, in which case we must interpret it to mean that evidenced meaning.

The second type: Both meanings are equally predominant; and this, in turn, is of two kinds:

The first kind: One meaning is linguistic and the other is Fiqhi. In this case, the Fiqhi meaning takes priority unless there is an indication that what is meant is the linguistic meaning. An example is the verse (which means): {…and invoke Allaah for them (salli 'alayhim). Indeed, your invocations are reassurance for them.} [Quran 9:103]

Also, if the meaning may either be linguistic or 'Urfi (customary according to customs); then in such case, the 'Urfi (meaning) takes priority because it is predominant in the language, but if the meaning may be Fiqhi or 'Urfi, then the Fiqhi meaning takes priority because Sharee'ah is more worthy of being applied than customs……”

Allaah knows best.