Ibn ‘Umar (رضي الله عنه) immitates the Prophet (صلى الله عليه وسلم)
The Two Sahihs recorded that `A’ishah (رضي الله عنها) said, “The Messenger of Allah (صلى الله عليه وسلم) performed Witr during the first part, the middle and latter parts of the night. Then, later (in his life), he would perform it (only) during the latter part.”
`Abdullah bin `Umar (رضي الله عنه) used to pray during the night and would ask, “O Nafi`! Is it the latter part of the night yet” and if Nafi` said, “Yes,” Ibn `Umar (رضي الله عنه) would start supplicating to Allah and seeking His forgiveness until dawn.
This Hadith was collected by Ibn Abi Hatim.