A judge needs to define the reason.

Ref.: Shail Kumari Devi and Anr. Vs. Krishan Bhagwan Pathak @ Kishun B. Pathak [AIR 2008 SC 3006] in which the Hon’ble SC has not agreed to view that as a normal rule, the Magistrate should grant maintenance only from the date of the order and not from the date of the application for maintenance, and in case magistrate intents to pass such an order, he is required to record reasons in support of such order. The magistrate is not required to record special reasons, if he intends to order maintenance from the date of application as there is nothing in S. 125 (2) which requires so. However, the magistrate must record reasons as envisaged by Sub-section (6) of S. 354 of the Code in support of the order passed by him.

The Apex Court held;

“-- while deciding an application under Section 125 of the code, a Magistrate is required to record reasons for granting or refusing to grant maintenance to wives, children or parents. Such maintenance can be awarded from the date of the order, or, if so ordered, from the date of the application for maintenance, as the case may be. For awarding maintenance from the date of the application, express order is necessary. No special reasons, however, are required to be recorded by the Court.”