Yahya related to me from Malik from Hisham ibn Urwa from hisfather that Abdullah ibn Masud said, "I do not mind if the iqama forthe subh prayer is called while I am still praying witr." (IT)
App reference (IT): Book 7, Hadith 25 (IT)
USC-MSA web (English) reference: Book 7, Hadith 25 (IT)
Arabic reference (IT): Book 7, Hadith 279 (IT)