He (Nafi') said: "So when Ibn 'Umar purchased something while he was sitting, he would stand to complete the sale."
In-book : Book 14, Hadith 45
English translation : Vol. 1, Book 12, Hadith 1245
14. The Book on Business
باب مَا جَاءَ أَنَّ مَسْحَ الرَّأْسِ مَرَّةٌ