[24].Surah An-Nur [The Light]: Ayat 53

৫৩. তারা দৃঢ়ভাবে আল্লাহর কসম খেয়ে বলে যে, আপনি তাদেরকে আদেশ করলে তারা সবকিছু ছেড়ে বের হবেই। বলুনঃ তোমরা কসম খেয়ো না। নিয়মানুযায়ী তোমাদের আনুগত্য, তোমরা যা কিছু কর নিশ্চয় আল্লাহ সে বিষয়ে জ্ঞাত।

Ayat 53. They swear by Allah their strongest oaths, that if only you would order them, they would leave (their homes for fighting in Allah's Cause). Say: "Swear you not; (this) obedience (of yours) is known (to be false). Verily, Allah knows well what you do." 

[Tafseer] of Ayat 53. They swear their strongest oaths by Allah that, if only thou wouldst command them, they would leave (their homes). Say: "Swear ye not; Obedience is (more) reasonable; verily, Allah is well acquainted with all that ye do." Some people, especially hypocrites, give hyperbolic assurances, as did the Madinah Hypocrites to the Holy Prophet, that they would do any bidding, even to the forsaking of their hearths and homes. To this they are ready to swear their strongest oaths, which mean nothing. They are asked to spare their oaths, and quietly do at least such unheroic duties as they are asked to do in everyday life. Idle words are not of the least value. Allah will judge by your actions, and He knows all, whether it is open or secret. 

Hazrat Abu Ayyub (May Allah be pleased with him) reported: The Messenger of Allah [SAWW](PBUH) said, "He who observes As-Saum (the fasts) in the month of Ramadan, and also observes As-Saum for six days in the month of Shawwal, it is as if he has observed As-Saum for the whole year.''   [Muslim Book 06, Chapter 36, Hadith # 2614]. 

Lesson : as mentioned above in Surah An-Nur Ayat 53."Verily, Allah knows well what you do." According to the formula that there is at least ten-fold reward for every virtue, the Saum of one month (Ramadan) are equivalent to Saum of ten months. If one also observes six days of Saum of Shawwal, they will be equal to Saum of two months. Thus, one becomes eligible for the reward of one full years' Saum. He who makes it a permanent feature is like one who observes Saum throughout his life. He will be considered by Allah as one who observes Saum permanently. Although voluntary in nature, they are highly important. One can observe these six-day Saum at a stretch or with intervals, but their observance one after the other at the beginning of the month is better. Similarly, if a person has missed some Saum of Ramadan due to illness, travelling etc., he should first make up the shortfall and then observe the voluntary six-day Saum of Shawwal.