What is Istis'hab? How can we apply this Islamic principle in our lives?
Bismillah hir-Rahman nir-Rahim. Allahumma salli ala Muhammadin wa aali Muhammad. One of the beautiful Islamic laws that we have is what is called "the law of continuity." In Arabic, scholars call this "Istishab."
In one very beautiful narration, the 6th Imam of Ahlul Bayt, Al Imam Ja'far Ibn Muhammad As-Sadiq, salawatullahi wa assalamu alayh, he teaches his companion, Zurara, a beautiful Islamic principle. Scholars, 14th centuries later, are so fascinated by this law, they have extracted thousands of rulings from this one law.
The Imam, alayhi assalam, says to Zurara, using four words in Arabic, "La taunkud al-yaqeena bish-shakk" - "do not negate certainty with doubt." This is a beautiful Islamic principle that we have in our legal system.
If you have previous certainty, and now you have a doubt, did that previous state change or no? This law states that you assume that previous certainty continues into the present state, until you have a new certainty that the previous state has ended.
I will share with you a few quick examples: at 12:00 p.m. you did wudhu, at 3 p.m., you start to have doubts, did I invalidate that wudhu or no? Did I sleep, did I use the restroom, I do not know. Am I on Wudhu now or no? Per the law of continuity, yes, you assume yourself to be on purity now; why? Because you are certain at 12:00 p.m. you did wudhu, but now you have a doubt as to whether you invalidated the wudhu or not. Therefore, you are considered to be on wudhu.
Let us apply this now to fasting as we are in the month of Ramadan. There are two common scenarios in which we can apply this law. Let us say it is early morning; you are not sure if the time of Fajr set in, you do not really know if now you have to stop eating or not? It is 5:00 a.m., did the Fajr set in or maybe it is in a few minutes? You have a doubt and you could not figure out whether the Fajr set in? Per the law of continuity, you can assume it is still night because 20 minutes ago you were sure, certain, a hundred percent it is night, it is not Fajr yet. Now you doubt whether the Fajr set in. Per the law of continuity, you can continue to eat and drink until you have confidence, certainty or yakeen that Fajr has set in.
The second example is when we are close to sunset, let us say you are at someplace and you are not sure if Maghrib has set in. Did the time for Maghrib now come, so I can break my fast or no? I still need a few more minutes. Per the law of continuity, you have to continue your fast until you are certain you are confident that the Maghrib set in.
Why? Because the law of continuity tells you - ten minutes ago, 15 minutes ago, you were sure, you were positive, you were certain that it is day; now you have doubt whether Maghrib set in, therefore you have to continue that previous state and per the law of continuity, it would not be permissible for you to break your fast until you are sure or confident that Maghrib has set in.
See how many beautiful laws our scholars are able to extract from this beautiful hadith of Al Imam As Sadiq, salawatullahi alayh.