When is it recommended to perform the Witr Prayer alone: after 'Isha' or before Fajr?

If the intent behind 'shaf'' (even) is what is performed before the 'witr' (odd) rak'ah as a part of it, then the time for performing these two rak'ahs follows the time for performing the witr. It is therefore preferable to pray them in the last part of the night for those who do not fear missing them; otherwise, they should be prayed before sleep. It is permissible to perform the two rak'ahs of shaf' and delay the third rak'ah of witr, whether a prayer or sleep separates them, as mentioned by the scholar Al-Ramli.