Muwatta Malik, Book 7, Hadith 20 (USC-MSA) ⓘ
Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to say the taslim between the two rakas and the one raka of witr so that he could order something he needed.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يُسَلِّمُ بَيْنَ الرَّكْعَتَيْنِ وَالرَّكْعَةِ فِي الْوِتْرِ حَتَّى يَأْمُرَ بِبَعْضِ حَاجَتِهِ .
also referenced under: Book 7, Hadith 274 (In-Book)