Is it permissible to retract the intention to fast a missed Ramadan day after the 'Isha prayer and two hours before Fajr?

There is no harm in retracting the intention to make up a fast before Fajr, because the time for fasting has not yet begun. It is permissible to delay making up the fast as long as there is ample time, but hastening to make it up is more virtuous to absolve oneself and to hasten to obedience. However, it becomes obligatory to hasten if time becomes limited.