Muwatta Malik 235

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ سَأَلَ ابْنَ شِهَابٍ عَنِ الْكَلاَمِ، يَوْمَ الْجُمُعَةِ إِذَا نَزَلَ الإِمَامُ عَنِ الْمِنْبَرِ، قَبْلَ أَنْ يُكَبِّرَ، ‏.‏ فَقَالَ ابْنُ شِهَابٍ لاَ بَأْسَ بِذَلِكَ ‏.‏

Yahya related to me from Malik that he asked Ibn Shihab about talking in the jumua after the imam had come down from the mimbar but before he had said the takbir. Ibn Shihab said, "There is no harm in that

Reference

Muwatta Malik 235

In-book

Book 5, Hadith 11