What is the correct interpretation of the Hadith "sleeping on a witr" and what is meant by it? And is praying rak'ahs after Witr and before Fajr reprehensible (makruh)?

Whoever resolves to perform the night vigil (Qiyam al-Layl) should defer the Witr prayer to make it the last of his prayers at night, in accordance with the hadith: "Make the last of your prayers at night Witr." As for one who has prayed Witr after Isha' and then wakes up for the night vigil, he should pray as much as he wishes and not perform Witr again. This is based on the hadith of Abu Hurayrah (may Allah be pleased with him) concerning one who is not confident of waking up.