The time of Imsak and eating after the break of dawn

Q 1: I have read the first volume of Tafsir (explanation/exegesis of the meanings of the Qur'an) Al-Manar by Sheikh Rashid Rida, in which he mentioned that a fasting person should abstain from eating and drinking [and anything that breaks the fast] twenty minutes before the Adhan (Call to prayer) of Fajr, as a precautionary measure. (Part No. 10; Page No. 283) What is the estimated period of time between Imsak and Fajr Adhan in Ramadan? What is the ruling on whomever hears Mu'adhin (caller to Prayer) say 'al-salatu khairun min-al-nawm (Prayer is better than sleep)', but takes a drink of water thinking that it is not wrong so long as Adhan has not finished yet. Is this permissible?What is the ruling regarding whoever has a drink of water while hearing Adhan for Fajr (Dawn) Prayer? Is this person's Sawm (Fast) valid, or not? Other people continue eating, drinking and smoking until the very time of Adhan claiming that this is permissible. A young man told me that he takes a drink of water while he hears me calling the Adhan for Fajr Prayer. What is the ruling on whomever does this intentionally?

A: The basic reference regarding Imsak and Iftar (breaking the Fast) is Allah's statement, ...and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night), then complete your Saum (fast) till the nightfall. Subsequently, eating and drinking is permissible until the advent of the Fajr when the white streak appears, which Allah made a sign which marks the time of abstention from eating and drinking and other matters. On the other hand, when the second Fajr or what is called Al-Fajr-ul-Sadiq (true dawn) is due, eating, drinking and other things which nullify Sawm are prohibited. If someone gets a drink of water after the break of the second Fajr, he will have to make up for that day. If he does so before the break of the second Fajr, he will not be required to make up for fasting on that day.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.