Nafi' reported that Abu Lubaba happened to pass by Ibn 'Umar who lived in the fortified place near the house of 'Umar b. Khattab and was busy in keeping his eyes upon a snake and killing it, the rest of the hadith is the same.

وَحَدَّثَنَا هَارُونُ بْنُ سَعِيدٍ الأَيْلِيُّ، حَدَّثَنَا ابْنُ وَهْبٍ، حَدَّثَنِي أُسَامَةُ، أَنَّ نَافِعًا، حَدَّثَهُ أَنَّ أَبَا لُبَابَةَ مَرَّ بِابْنِ عُمَرَ وَهُوَ عِنْدَ الأُطُمِ الَّذِي عِنْدَ دَارِ عُمَرَ بْنِ الْخَطَّابِ يَرْصُدُ حَيَّةً بِنَحْوِ حَدِيثِ اللَّيْثِ بْنِ سَعْدٍ ‏.‏